Fixed database typo and removed unnecessary class identifier.

venv/Lib/site-packages/networkx/drawing/__init__.py

@@ -0,0 +1,6 @@
+# graph drawing and interface to graphviz
+
+from .layout import *
+from .nx_pylab import *
+from . import nx_agraph
+from . import nx_pydot

venv/Lib/site-packages/networkx/drawing/nx_agraph.py

@@ -0,0 +1,483 @@
+"""
+***************
+Graphviz AGraph
+***************
+
+Interface to pygraphviz AGraph class.
+
+Examples
+--------
+>>> G = nx.complete_graph(5)
+>>> A = nx.nx_agraph.to_agraph(G)
+>>> H = nx.nx_agraph.from_agraph(A)
+
+See Also
+--------
+Pygraphviz: http://pygraphviz.github.io/
+"""
+import os
+import tempfile
+import networkx as nx
+
+__all__ = [
+    "from_agraph",
+    "to_agraph",
+    "write_dot",
+    "read_dot",
+    "graphviz_layout",
+    "pygraphviz_layout",
+    "view_pygraphviz",
+]
+
+
+def from_agraph(A, create_using=None):
+    """Returns a NetworkX Graph or DiGraph from a PyGraphviz graph.
+
+    Parameters
+    ----------
+    A : PyGraphviz AGraph
+      A graph created with PyGraphviz
+
+    create_using : NetworkX graph constructor, optional (default=None)
+       Graph type to create. If graph instance, then cleared before populated.
+       If `None`, then the appropriate Graph type is inferred from `A`.
+
+    Examples
+    --------
+    >>> K5 = nx.complete_graph(5)
+    >>> A = nx.nx_agraph.to_agraph(K5)
+    >>> G = nx.nx_agraph.from_agraph(A)
+
+    Notes
+    -----
+    The Graph G will have a dictionary G.graph_attr containing
+    the default graphviz attributes for graphs, nodes and edges.
+
+    Default node attributes will be in the dictionary G.node_attr
+    which is keyed by node.
+
+    Edge attributes will be returned as edge data in G.  With
+    edge_attr=False the edge data will be the Graphviz edge weight
+    attribute or the value 1 if no edge weight attribute is found.
+
+    """
+    if create_using is None:
+        if A.is_directed():
+            if A.is_strict():
+                create_using = nx.DiGraph
+            else:
+                create_using = nx.MultiDiGraph
+        else:
+            if A.is_strict():
+                create_using = nx.Graph
+            else:
+                create_using = nx.MultiGraph
+
+    # assign defaults
+    N = nx.empty_graph(0, create_using)
+    if A.name is not None:
+        N.name = A.name
+
+    # add graph attributes
+    N.graph.update(A.graph_attr)
+
+    # add nodes, attributes to N.node_attr
+    for n in A.nodes():
+        str_attr = {str(k): v for k, v in n.attr.items()}
+        N.add_node(str(n), **str_attr)
+
+    # add edges, assign edge data as dictionary of attributes
+    for e in A.edges():
+        u, v = str(e[0]), str(e[1])
+        attr = dict(e.attr)
+        str_attr = {str(k): v for k, v in attr.items()}
+        if not N.is_multigraph():
+            if e.name is not None:
+                str_attr["key"] = e.name
+            N.add_edge(u, v, **str_attr)
+        else:
+            N.add_edge(u, v, key=e.name, **str_attr)
+
+    # add default attributes for graph, nodes, and edges
+    # hang them on N.graph_attr
+    N.graph["graph"] = dict(A.graph_attr)
+    N.graph["node"] = dict(A.node_attr)
+    N.graph["edge"] = dict(A.edge_attr)
+    return N
+
+
+def to_agraph(N):
+    """Returns a pygraphviz graph from a NetworkX graph N.
+
+    Parameters
+    ----------
+    N : NetworkX graph
+      A graph created with NetworkX
+
+    Examples
+    --------
+    >>> K5 = nx.complete_graph(5)
+    >>> A = nx.nx_agraph.to_agraph(K5)
+
+    Notes
+    -----
+    If N has an dict N.graph_attr an attempt will be made first
+    to copy properties attached to the graph (see from_agraph)
+    and then updated with the calling arguments if any.
+
+    """
+    try:
+        import pygraphviz
+    except ImportError as e:
+        raise ImportError("requires pygraphviz " "http://pygraphviz.github.io/") from e
+    directed = N.is_directed()
+    strict = nx.number_of_selfloops(N) == 0 and not N.is_multigraph()
+    A = pygraphviz.AGraph(name=N.name, strict=strict, directed=directed)
+
+    # default graph attributes
+    A.graph_attr.update(N.graph.get("graph", {}))
+    A.node_attr.update(N.graph.get("node", {}))
+    A.edge_attr.update(N.graph.get("edge", {}))
+
+    A.graph_attr.update(
+        (k, v) for k, v in N.graph.items() if k not in ("graph", "node", "edge")
+    )
+
+    # add nodes
+    for n, nodedata in N.nodes(data=True):
+        A.add_node(n)
+        # Add node data
+        a = A.get_node(n)
+        a.attr.update({k: str(v) for k, v in nodedata.items()})
+
+    # loop over edges
+    if N.is_multigraph():
+        for u, v, key, edgedata in N.edges(data=True, keys=True):
+            str_edgedata = {k: str(v) for k, v in edgedata.items() if k != "key"}
+            A.add_edge(u, v, key=str(key))
+            # Add edge data
+            a = A.get_edge(u, v)
+            a.attr.update(str_edgedata)
+
+    else:
+        for u, v, edgedata in N.edges(data=True):
+            str_edgedata = {k: str(v) for k, v in edgedata.items()}
+            A.add_edge(u, v)
+            # Add edge data
+            a = A.get_edge(u, v)
+            a.attr.update(str_edgedata)
+
+    return A
+
+
+def write_dot(G, path):
+    """Write NetworkX graph G to Graphviz dot format on path.
+
+    Parameters
+    ----------
+    G : graph
+       A networkx graph
+    path : filename
+       Filename or file handle to write
+    """
+    A = to_agraph(G)
+    A.write(path)
+    A.clear()
+    return
+
+
+def read_dot(path):
+    """Returns a NetworkX graph from a dot file on path.
+
+    Parameters
+    ----------
+    path : file or string
+       File name or file handle to read.
+    """
+    try:
+        import pygraphviz
+    except ImportError as e:
+        raise ImportError(
+            "read_dot() requires pygraphviz " "http://pygraphviz.github.io/"
+        ) from e
+    A = pygraphviz.AGraph(file=path)
+    gr = from_agraph(A)
+    A.clear()
+    return gr
+
+
+def graphviz_layout(G, prog="neato", root=None, args=""):
+    """Create node positions for G using Graphviz.
+
+    Parameters
+    ----------
+    G : NetworkX graph
+      A graph created with NetworkX
+    prog : string
+      Name of Graphviz layout program
+    root : string, optional
+      Root node for twopi layout
+    args : string, optional
+      Extra arguments to Graphviz layout program
+
+    Returns
+    -------
+      Dictionary of x, y, positions keyed by node.
+
+    Examples
+    --------
+    >>> G = nx.petersen_graph()
+    >>> pos = nx.nx_agraph.graphviz_layout(G)
+    >>> pos = nx.nx_agraph.graphviz_layout(G, prog="dot")
+
+    Notes
+    -----
+    This is a wrapper for pygraphviz_layout.
+    """
+    return pygraphviz_layout(G, prog=prog, root=root, args=args)
+
+
+def pygraphviz_layout(G, prog="neato", root=None, args=""):
+    """Create node positions for G using Graphviz.
+
+    Parameters
+    ----------
+    G : NetworkX graph
+      A graph created with NetworkX
+    prog : string
+      Name of Graphviz layout program
+    root : string, optional
+      Root node for twopi layout
+    args : string, optional
+      Extra arguments to Graphviz layout program
+
+    Returns
+    -------
+    node_pos : dict
+      Dictionary of x, y, positions keyed by node.
+
+    Examples
+    --------
+    >>> G = nx.petersen_graph()
+    >>> pos = nx.nx_agraph.graphviz_layout(G)
+    >>> pos = nx.nx_agraph.graphviz_layout(G, prog="dot")
+
+    Notes
+    -----
+    If you use complex node objects, they may have the same string
+    representation and GraphViz could treat them as the same node.
+    The layout may assign both nodes a single location. See Issue #1568
+    If this occurs in your case, consider relabeling the nodes just
+    for the layout computation using something similar to::
+
+        >>> H = nx.convert_node_labels_to_integers(G, label_attribute="node_label")
+        >>> H_layout = nx.nx_agraph.pygraphviz_layout(G, prog="dot")
+        >>> G_layout = {H.nodes[n]["node_label"]: p for n, p in H_layout.items()}
+
+    """
+    try:
+        import pygraphviz
+    except ImportError as e:
+        raise ImportError("requires pygraphviz " "http://pygraphviz.github.io/") from e
+    if root is not None:
+        args += f"-Groot={root}"
+    A = to_agraph(G)
+    A.layout(prog=prog, args=args)
+    node_pos = {}
+    for n in G:
+        node = pygraphviz.Node(A, n)
+        try:
+            xs = node.attr["pos"].split(",")
+            node_pos[n] = tuple(float(x) for x in xs)
+        except:
+            print("no position for node", n)
+            node_pos[n] = (0.0, 0.0)
+    return node_pos
+
+
+@nx.utils.open_file(5, "w+b")
+def view_pygraphviz(
+    G, edgelabel=None, prog="dot", args="", suffix="", path=None, show=True
+):
+    """Views the graph G using the specified layout algorithm.
+
+    Parameters
+    ----------
+    G : NetworkX graph
+        The machine to draw.
+    edgelabel : str, callable, None
+        If a string, then it specifes the edge attribute to be displayed
+        on the edge labels. If a callable, then it is called for each
+        edge and it should return the string to be displayed on the edges.
+        The function signature of `edgelabel` should be edgelabel(data),
+        where `data` is the edge attribute dictionary.
+    prog : string
+        Name of Graphviz layout program.
+    args : str
+        Additional arguments to pass to the Graphviz layout program.
+    suffix : str
+        If `filename` is None, we save to a temporary file.  The value of
+        `suffix` will appear at the tail end of the temporary filename.
+    path : str, None
+        The filename used to save the image.  If None, save to a temporary
+        file.  File formats are the same as those from pygraphviz.agraph.draw.
+    show : bool, default = True
+        Whether to display the graph with `networkx.utils.default_opener`,
+        default is `True`. If `False`, the rendered graph is still available
+        at `path`.
+
+    Returns
+    -------
+    path : str
+        The filename of the generated image.
+    A : PyGraphviz graph
+        The PyGraphviz graph instance used to generate the image.
+
+    Notes
+    -----
+    If this function is called in succession too quickly, sometimes the
+    image is not displayed. So you might consider time.sleep(.5) between
+    calls if you experience problems.
+
+    """
+    if not len(G):
+        raise nx.NetworkXException("An empty graph cannot be drawn.")
+
+    # If we are providing default values for graphviz, these must be set
+    # before any nodes or edges are added to the PyGraphviz graph object.
+    # The reason for this is that default values only affect incoming objects.
+    # If you change the default values after the objects have been added,
+    # then they inherit no value and are set only if explicitly set.
+
+    # to_agraph() uses these values.
+    attrs = ["edge", "node", "graph"]
+    for attr in attrs:
+        if attr not in G.graph:
+            G.graph[attr] = {}
+
+    # These are the default values.
+    edge_attrs = {"fontsize": "10"}
+    node_attrs = {
+        "style": "filled",
+        "fillcolor": "#0000FF40",
+        "height": "0.75",
+        "width": "0.75",
+        "shape": "circle",
+    }
+    graph_attrs = {}
+
+    def update_attrs(which, attrs):
+        # Update graph attributes. Return list of those which were added.
+        added = []
+        for k, v in attrs.items():
+            if k not in G.graph[which]:
+                G.graph[which][k] = v
+                added.append(k)
+
+    def clean_attrs(which, added):
+        # Remove added attributes
+        for attr in added:
+            del G.graph[which][attr]
+        if not G.graph[which]:
+            del G.graph[which]
+
+    # Update all default values
+    update_attrs("edge", edge_attrs)
+    update_attrs("node", node_attrs)
+    update_attrs("graph", graph_attrs)
+
+    # Convert to agraph, so we inherit default values
+    A = to_agraph(G)
+
+    # Remove the default values we added to the original graph.
+    clean_attrs("edge", edge_attrs)
+    clean_attrs("node", node_attrs)
+    clean_attrs("graph", graph_attrs)
+
+    # If the user passed in an edgelabel, we update the labels for all edges.
+    if edgelabel is not None:
+        if not hasattr(edgelabel, "__call__"):
+
+            def func(data):
+                return "".join(["  ", str(data[edgelabel]), "  "])
+
+        else:
+            func = edgelabel
+
+        # update all the edge labels
+        if G.is_multigraph():
+            for u, v, key, data in G.edges(keys=True, data=True):
+                # PyGraphviz doesn't convert the key to a string. See #339
+                edge = A.get_edge(u, v, str(key))
+                edge.attr["label"] = str(func(data))
+        else:
+            for u, v, data in G.edges(data=True):
+                edge = A.get_edge(u, v)
+                edge.attr["label"] = str(func(data))
+
+    if path is None:
+        ext = "png"
+        if suffix:
+            suffix = f"_{suffix}.{ext}"
+        else:
+            suffix = f".{ext}"
+        path = tempfile.NamedTemporaryFile(suffix=suffix, delete=False)
+    else:
+        # Assume the decorator worked and it is a file-object.
+        pass
+
+    # Write graph to file
+    A.draw(path=path, format=None, prog=prog, args=args)
+    path.close()
+
+    # Show graph in a new window (depends on platform configuration)
+    if show:
+        nx.utils.default_opener(path.name)
+
+    return path.name, A
+
+
+def display_pygraphviz(graph, path, format=None, prog=None, args=""):
+    """Internal function to display a graph in OS dependent manner.
+
+    Parameters
+    ----------
+    graph : PyGraphviz graph
+        A PyGraphviz AGraph instance.
+    path :  file object
+        An already opened file object that will be closed.
+    format : str, None
+        An attempt is made to guess the output format based on the extension
+        of the filename. If that fails, the value of `format` is used.
+    prog : string
+        Name of Graphviz layout program.
+    args : str
+        Additional arguments to pass to the Graphviz layout program.
+
+    Notes
+    -----
+    If this function is called in succession too quickly, sometimes the
+    image is not displayed. So you might consider time.sleep(.5) between
+    calls if you experience problems.
+
+    """
+    import warnings
+
+    warnings.warn(
+        "display_pygraphviz is deprecated and will be removed in NetworkX 3.0. "
+        "To view a graph G using pygraphviz, use nx.nx_agraph.view_pygraphviz(G). "
+        "To view a graph from file, consider nx.utils.default_opener(filename).",
+        DeprecationWarning,
+    )
+    if format is None:
+        filename = path.name
+        format = os.path.splitext(filename)[1].lower()[1:]
+    if not format:
+        # Let the draw() function use its default
+        format = None
+
+    # Save to a file and display in the default viewer.
+    # We must close the file before viewing it.
+    graph.draw(path, format, prog, args)
+    path.close()
+    nx.utils.default_opener(filename)

venv/Lib/site-packages/networkx/drawing/nx_pydot.py

@@ -0,0 +1,338 @@
+"""
+*****
+Pydot
+*****
+
+Import and export NetworkX graphs in Graphviz dot format using pydot.
+
+Either this module or nx_agraph can be used to interface with graphviz.
+
+See Also
+--------
+pydot:         https://github.com/erocarrera/pydot
+Graphviz:      https://www.graphviz.org
+DOT Language:  http://www.graphviz.org/doc/info/lang.html
+"""
+from locale import getpreferredencoding
+from networkx.utils import open_file
+import networkx as nx
+
+__all__ = [
+    "write_dot",
+    "read_dot",
+    "graphviz_layout",
+    "pydot_layout",
+    "to_pydot",
+    "from_pydot",
+]
+
+
+@open_file(1, mode="w")
+def write_dot(G, path):
+    """Write NetworkX graph G to Graphviz dot format on path.
+
+    Path can be a string or a file handle.
+    """
+    P = to_pydot(G)
+    path.write(P.to_string())
+    return
+
+
+@open_file(0, mode="r")
+def read_dot(path):
+    """Returns a NetworkX :class:`MultiGraph` or :class:`MultiDiGraph` from the
+    dot file with the passed path.
+
+    If this file contains multiple graphs, only the first such graph is
+    returned. All graphs _except_ the first are silently ignored.
+
+    Parameters
+    ----------
+    path : str or file
+        Filename or file handle.
+
+    Returns
+    -------
+    G : MultiGraph or MultiDiGraph
+        A :class:`MultiGraph` or :class:`MultiDiGraph`.
+
+    Notes
+    -----
+    Use `G = nx.Graph(read_dot(path))` to return a :class:`Graph` instead of a
+    :class:`MultiGraph`.
+    """
+    import pydot
+
+    data = path.read()
+
+    # List of one or more "pydot.Dot" instances deserialized from this file.
+    P_list = pydot.graph_from_dot_data(data)
+
+    # Convert only the first such instance into a NetworkX graph.
+    return from_pydot(P_list[0])
+
+
+def from_pydot(P):
+    """Returns a NetworkX graph from a Pydot graph.
+
+    Parameters
+    ----------
+    P : Pydot graph
+      A graph created with Pydot
+
+    Returns
+    -------
+    G : NetworkX multigraph
+        A MultiGraph or MultiDiGraph.
+
+    Examples
+    --------
+    >>> K5 = nx.complete_graph(5)
+    >>> A = nx.nx_pydot.to_pydot(K5)
+    >>> G = nx.nx_pydot.from_pydot(A)  # return MultiGraph
+
+    # make a Graph instead of MultiGraph
+    >>> G = nx.Graph(nx.nx_pydot.from_pydot(A))
+
+    """
+    if P.get_strict(None):  # pydot bug: get_strict() shouldn't take argument
+        multiedges = False
+    else:
+        multiedges = True
+
+    if P.get_type() == "graph":  # undirected
+        if multiedges:
+            N = nx.MultiGraph()
+        else:
+            N = nx.Graph()
+    else:
+        if multiedges:
+            N = nx.MultiDiGraph()
+        else:
+            N = nx.DiGraph()
+
+    # assign defaults
+    name = P.get_name().strip('"')
+    if name != "":
+        N.name = name
+
+    # add nodes, attributes to N.node_attr
+    for p in P.get_node_list():
+        n = p.get_name().strip('"')
+        if n in ("node", "graph", "edge"):
+            continue
+        N.add_node(n, **p.get_attributes())
+
+    # add edges
+    for e in P.get_edge_list():
+        u = e.get_source()
+        v = e.get_destination()
+        attr = e.get_attributes()
+        s = []
+        d = []
+
+        if isinstance(u, str):
+            s.append(u.strip('"'))
+        else:
+            for unodes in u["nodes"]:
+                s.append(unodes.strip('"'))
+
+        if isinstance(v, str):
+            d.append(v.strip('"'))
+        else:
+            for vnodes in v["nodes"]:
+                d.append(vnodes.strip('"'))
+
+        for source_node in s:
+            for destination_node in d:
+                N.add_edge(source_node, destination_node, **attr)
+
+    # add default attributes for graph, nodes, edges
+    pattr = P.get_attributes()
+    if pattr:
+        N.graph["graph"] = pattr
+    try:
+        N.graph["node"] = P.get_node_defaults()[0]
+    except (IndexError, TypeError):
+        pass  # N.graph['node']={}
+    try:
+        N.graph["edge"] = P.get_edge_defaults()[0]
+    except (IndexError, TypeError):
+        pass  # N.graph['edge']={}
+    return N
+
+
+def to_pydot(N):
+    """Returns a pydot graph from a NetworkX graph N.
+
+    Parameters
+    ----------
+    N : NetworkX graph
+      A graph created with NetworkX
+
+    Examples
+    --------
+    >>> K5 = nx.complete_graph(5)
+    >>> P = nx.nx_pydot.to_pydot(K5)
+
+    Notes
+    -----
+
+    """
+    import pydot
+
+    # set Graphviz graph type
+    if N.is_directed():
+        graph_type = "digraph"
+    else:
+        graph_type = "graph"
+    strict = nx.number_of_selfloops(N) == 0 and not N.is_multigraph()
+
+    name = N.name
+    graph_defaults = N.graph.get("graph", {})
+    if name == "":
+        P = pydot.Dot("", graph_type=graph_type, strict=strict, **graph_defaults)
+    else:
+        P = pydot.Dot(
+            f'"{name}"', graph_type=graph_type, strict=strict, **graph_defaults
+        )
+    try:
+        P.set_node_defaults(**N.graph["node"])
+    except KeyError:
+        pass
+    try:
+        P.set_edge_defaults(**N.graph["edge"])
+    except KeyError:
+        pass
+
+    for n, nodedata in N.nodes(data=True):
+        str_nodedata = {k: str(v) for k, v in nodedata.items()}
+        p = pydot.Node(str(n), **str_nodedata)
+        P.add_node(p)
+
+    if N.is_multigraph():
+        for u, v, key, edgedata in N.edges(data=True, keys=True):
+            str_edgedata = {k: str(v) for k, v in edgedata.items() if k != "key"}
+            edge = pydot.Edge(str(u), str(v), key=str(key), **str_edgedata)
+            P.add_edge(edge)
+
+    else:
+        for u, v, edgedata in N.edges(data=True):
+            str_edgedata = {k: str(v) for k, v in edgedata.items()}
+            edge = pydot.Edge(str(u), str(v), **str_edgedata)
+            P.add_edge(edge)
+    return P
+
+
+def graphviz_layout(G, prog="neato", root=None):
+    """Create node positions using Pydot and Graphviz.
+
+    Returns a dictionary of positions keyed by node.
+
+    Parameters
+    ----------
+    G : NetworkX Graph
+        The graph for which the layout is computed.
+    prog : string (default: 'neato')
+        The name of the GraphViz program to use for layout.
+        Options depend on GraphViz version but may include:
+        'dot', 'twopi', 'fdp', 'sfdp', 'circo'
+    root : Node from G or None (default: None)
+        The node of G from which to start some layout algorithms.
+
+    Returns
+    -------
+      Dictionary of (x, y) positions keyed by node.
+
+    Examples
+    --------
+    >>> G = nx.complete_graph(4)
+    >>> pos = nx.nx_pydot.graphviz_layout(G)
+    >>> pos = nx.nx_pydot.graphviz_layout(G, prog="dot")
+
+    Notes
+    -----
+    This is a wrapper for pydot_layout.
+    """
+    return pydot_layout(G=G, prog=prog, root=root)
+
+
+def pydot_layout(G, prog="neato", root=None):
+    """Create node positions using :mod:`pydot` and Graphviz.
+
+    Parameters
+    --------
+    G : Graph
+        NetworkX graph to be laid out.
+    prog : string  (default: 'neato')
+        Name of the GraphViz command to use for layout.
+        Options depend on GraphViz version but may include:
+        'dot', 'twopi', 'fdp', 'sfdp', 'circo'
+    root : Node from G or None (default: None)
+        The node of G from which to start some layout algorithms.
+
+    Returns
+    --------
+    dict
+        Dictionary of positions keyed by node.
+
+    Examples
+    --------
+    >>> G = nx.complete_graph(4)
+    >>> pos = nx.nx_pydot.pydot_layout(G)
+    >>> pos = nx.nx_pydot.pydot_layout(G, prog="dot")
+
+    Notes
+    -----
+    If you use complex node objects, they may have the same string
+    representation and GraphViz could treat them as the same node.
+    The layout may assign both nodes a single location. See Issue #1568
+    If this occurs in your case, consider relabeling the nodes just
+    for the layout computation using something similar to:
+
+        H = nx.convert_node_labels_to_integers(G, label_attribute='node_label')
+        H_layout = nx.nx_pydot.pydot_layout(G, prog='dot')
+        G_layout = {H.nodes[n]['node_label']: p for n, p in H_layout.items()}
+
+    """
+    import pydot
+
+    P = to_pydot(G)
+    if root is not None:
+        P.set("root", str(root))
+
+    # List of low-level bytes comprising a string in the dot language converted
+    # from the passed graph with the passed external GraphViz command.
+    D_bytes = P.create_dot(prog=prog)
+
+    # Unique string decoded from these bytes with the preferred locale encoding
+    D = str(D_bytes, encoding=getpreferredencoding())
+
+    if D == "":  # no data returned
+        print(f"Graphviz layout with {prog} failed")
+        print()
+        print("To debug what happened try:")
+        print("P = nx.nx_pydot.to_pydot(G)")
+        print('P.write_dot("file.dot")')
+        print(f"And then run {prog} on file.dot")
+        return
+
+    # List of one or more "pydot.Dot" instances deserialized from this string.
+    Q_list = pydot.graph_from_dot_data(D)
+    assert len(Q_list) == 1
+
+    # The first and only such instance, as guaranteed by the above assertion.
+    Q = Q_list[0]
+
+    node_pos = {}
+    for n in G.nodes():
+        pydot_node = pydot.Node(str(n)).get_name()
+        node = Q.get_node(pydot_node)
+
+        if isinstance(node, list):
+            node = node[0]
+        pos = node.get_pos()[1:-1]  # strip leading and trailing double quotes
+        if pos is not None:
+            xx, yy = pos.split(",")
+            node_pos[n] = (float(xx), float(yy))
+    return node_pos

venv/Lib/site-packages/networkx/drawing/tests/test_agraph.py

@@ -0,0 +1,249 @@
+"""Unit tests for PyGraphviz interface."""
+import os
+import tempfile
+import pytest
+
+pygraphviz = pytest.importorskip("pygraphviz")
+
+
+from networkx.testing import assert_edges_equal, assert_nodes_equal, assert_graphs_equal
+
+import networkx as nx
+
+
+class TestAGraph:
+    def build_graph(self, G):
+        edges = [("A", "B"), ("A", "C"), ("A", "C"), ("B", "C"), ("A", "D")]
+        G.add_edges_from(edges)
+        G.add_node("E")
+        G.graph["metal"] = "bronze"
+        return G
+
+    def assert_equal(self, G1, G2):
+        assert_nodes_equal(G1.nodes(), G2.nodes())
+        assert_edges_equal(G1.edges(), G2.edges())
+        assert G1.graph["metal"] == G2.graph["metal"]
+
+    def agraph_checks(self, G):
+        G = self.build_graph(G)
+        A = nx.nx_agraph.to_agraph(G)
+        H = nx.nx_agraph.from_agraph(A)
+        self.assert_equal(G, H)
+
+        fname = tempfile.mktemp()
+        nx.drawing.nx_agraph.write_dot(H, fname)
+        Hin = nx.nx_agraph.read_dot(fname)
+        os.unlink(fname)
+        self.assert_equal(H, Hin)
+
+        (fd, fname) = tempfile.mkstemp()
+        with open(fname, "w") as fh:
+            nx.drawing.nx_agraph.write_dot(H, fh)
+
+        with open(fname) as fh:
+            Hin = nx.nx_agraph.read_dot(fh)
+        os.unlink(fname)
+        self.assert_equal(H, Hin)
+
+    def test_from_agraph_name(self):
+        G = nx.Graph(name="test")
+        A = nx.nx_agraph.to_agraph(G)
+        H = nx.nx_agraph.from_agraph(A)
+        assert G.name == "test"
+
+    @pytest.mark.parametrize(
+        "graph_class", (nx.Graph, nx.DiGraph, nx.MultiGraph, nx.MultiDiGraph)
+    )
+    def test_from_agraph_create_using(self, graph_class):
+        G = nx.path_graph(3)
+        A = nx.nx_agraph.to_agraph(G)
+        H = nx.nx_agraph.from_agraph(A, create_using=graph_class)
+        assert isinstance(H, graph_class)
+
+    def test_from_agraph_named_edges(self):
+        # Create an AGraph from an existing (non-multi) Graph
+        G = nx.Graph()
+        G.add_nodes_from([0, 1])
+        A = nx.nx_agraph.to_agraph(G)
+        # Add edge (+ name, given by key) to the AGraph
+        A.add_edge(0, 1, key="foo")
+        # Verify a.name roundtrips out to 'key' in from_agraph
+        H = nx.nx_agraph.from_agraph(A)
+        assert isinstance(H, nx.Graph)
+        assert ("0", "1", {"key": "foo"}) in H.edges(data=True)
+
+    def test_undirected(self):
+        self.agraph_checks(nx.Graph())
+
+    def test_directed(self):
+        self.agraph_checks(nx.DiGraph())
+
+    def test_multi_undirected(self):
+        self.agraph_checks(nx.MultiGraph())
+
+    def test_multi_directed(self):
+        self.agraph_checks(nx.MultiDiGraph())
+
+    def test_to_agraph_with_nodedata(self):
+        G = nx.Graph()
+        G.add_node(1, color="red")
+        A = nx.nx_agraph.to_agraph(G)
+        assert dict(A.nodes()[0].attr) == {"color": "red"}
+
+    @pytest.mark.parametrize("graph_class", (nx.Graph, nx.MultiGraph))
+    def test_to_agraph_with_edgedata(self, graph_class):
+        G = graph_class()
+        G.add_nodes_from([0, 1])
+        G.add_edge(0, 1, color="yellow")
+        A = nx.nx_agraph.to_agraph(G)
+        assert dict(A.edges()[0].attr) == {"color": "yellow"}
+
+    def test_view_pygraphviz_path(self, tmp_path):
+        G = nx.complete_graph(3)
+        input_path = str(tmp_path / "graph.png")
+        out_path, A = nx.nx_agraph.view_pygraphviz(G, path=input_path, show=False)
+        assert out_path == input_path
+        # Ensure file is not empty
+        with open(input_path, "rb") as fh:
+            data = fh.read()
+        assert len(data) > 0
+
+    def test_view_pygraphviz_file_suffix(self, tmp_path):
+        G = nx.complete_graph(3)
+        path, A = nx.nx_agraph.view_pygraphviz(G, suffix=1, show=False)
+        assert path[-6:] == "_1.png"
+
+    def test_view_pygraphviz(self):
+        G = nx.Graph()  # "An empty graph cannot be drawn."
+        pytest.raises(nx.NetworkXException, nx.nx_agraph.view_pygraphviz, G)
+        G = nx.barbell_graph(4, 6)
+        nx.nx_agraph.view_pygraphviz(G, show=False)
+
+    def test_view_pygraphviz_edgelabel(self):
+        G = nx.Graph()
+        G.add_edge(1, 2, weight=7)
+        G.add_edge(2, 3, weight=8)
+        path, A = nx.nx_agraph.view_pygraphviz(G, edgelabel="weight", show=False)
+        for edge in A.edges():
+            assert edge.attr["weight"] in ("7", "8")
+
+    def test_view_pygraphviz_callable_edgelabel(self):
+        G = nx.complete_graph(3)
+
+        def foo_label(data):
+            return "foo"
+
+        path, A = nx.nx_agraph.view_pygraphviz(G, edgelabel=foo_label, show=False)
+        for edge in A.edges():
+            assert edge.attr["label"] == "foo"
+
+    def test_view_pygraphviz_multigraph_edgelabels(self):
+        G = nx.MultiGraph()
+        G.add_edge(0, 1, key=0, name="left_fork")
+        G.add_edge(0, 1, key=1, name="right_fork")
+        path, A = nx.nx_agraph.view_pygraphviz(G, edgelabel="name", show=False)
+        edges = A.edges()
+        assert len(edges) == 2
+        for edge in edges:
+            assert edge.attr["label"].strip() in ("left_fork", "right_fork")
+
+    def test_graph_with_reserved_keywords(self):
+        # test attribute/keyword clash case for #1582
+        # node: n
+        # edges: u,v
+        G = nx.Graph()
+        G = self.build_graph(G)
+        G.nodes["E"]["n"] = "keyword"
+        G.edges[("A", "B")]["u"] = "keyword"
+        G.edges[("A", "B")]["v"] = "keyword"
+        A = nx.nx_agraph.to_agraph(G)
+
+    def test_view_pygraphviz_no_added_attrs_to_input(self):
+        G = nx.complete_graph(2)
+        path, A = nx.nx_agraph.view_pygraphviz(G, show=False)
+        assert G.graph == {}
+
+    @pytest.mark.xfail(reason="known bug in clean_attrs")
+    def test_view_pygraphviz_leaves_input_graph_unmodified(self):
+        G = nx.complete_graph(2)
+        # Add entries to graph dict that to_agraph handles specially
+        G.graph["node"] = {"width": "0.80"}
+        G.graph["edge"] = {"fontsize": "14"}
+        path, A = nx.nx_agraph.view_pygraphviz(G, show=False)
+        assert G.graph == {"node": {"width": "0.80"}, "edge": {"fontsize": "14"}}
+
+    def test_graph_with_AGraph_attrs(self):
+        G = nx.complete_graph(2)
+        # Add entries to graph dict that to_agraph handles specially
+        G.graph["node"] = {"width": "0.80"}
+        G.graph["edge"] = {"fontsize": "14"}
+        path, A = nx.nx_agraph.view_pygraphviz(G, show=False)
+        # Ensure user-specified values are not lost
+        assert dict(A.node_attr)["width"] == "0.80"
+        assert dict(A.edge_attr)["fontsize"] == "14"
+
+    def test_round_trip_empty_graph(self):
+        G = nx.Graph()
+        A = nx.nx_agraph.to_agraph(G)
+        H = nx.nx_agraph.from_agraph(A)
+        # assert_graphs_equal(G, H)
+        AA = nx.nx_agraph.to_agraph(H)
+        HH = nx.nx_agraph.from_agraph(AA)
+        assert_graphs_equal(H, HH)
+        G.graph["graph"] = {}
+        G.graph["node"] = {}
+        G.graph["edge"] = {}
+        assert_graphs_equal(G, HH)
+
+    @pytest.mark.xfail(reason="integer->string node conversion in round trip")
+    def test_round_trip_integer_nodes(self):
+        G = nx.complete_graph(3)
+        A = nx.nx_agraph.to_agraph(G)
+        H = nx.nx_agraph.from_agraph(A)
+        assert_graphs_equal(G, H)
+
+    def test_graphviz_alias(self):
+        G = self.build_graph(nx.Graph())
+        pos_graphviz = nx.nx_agraph.graphviz_layout(G)
+        pos_pygraphviz = nx.nx_agraph.pygraphviz_layout(G)
+        assert pos_graphviz == pos_pygraphviz
+
+    @pytest.mark.parametrize("root", range(5))
+    def test_pygraphviz_layout_root(self, root):
+        # NOTE: test depends on layout prog being deterministic
+        G = nx.complete_graph(5)
+        A = nx.nx_agraph.to_agraph(G)
+        # Get layout with root arg is not None
+        pygv_layout = nx.nx_agraph.pygraphviz_layout(G, prog="circo", root=root)
+        # Equivalent layout directly on AGraph
+        A.layout(args=f"-Groot={root}", prog="circo")
+        # Parse AGraph layout
+        a1_pos = tuple(float(v) for v in dict(A.get_node("1").attr)["pos"].split(","))
+        assert pygv_layout[1] == a1_pos
+
+    def test_2d_layout(self):
+        G = nx.Graph()
+        G = self.build_graph(G)
+        G.graph["dimen"] = 2
+        pos = nx.nx_agraph.pygraphviz_layout(G, prog="neato")
+        pos = list(pos.values())
+        assert len(pos) == 5
+        assert len(pos[0]) == 2
+
+    def test_3d_layout(self):
+        G = nx.Graph()
+        G = self.build_graph(G)
+        G.graph["dimen"] = 3
+        pos = nx.nx_agraph.pygraphviz_layout(G, prog="neato")
+        pos = list(pos.values())
+        assert len(pos) == 5
+        assert len(pos[0]) == 3
+
+    def test_display_pygraphviz_deprecation_warning(self):
+        G = nx.complete_graph(2)
+        path_name, A = nx.nx_agraph.view_pygraphviz(G, show=False)
+        # Monkeypatch default_opener to prevent window opening
+        nx.utils.default_opener = lambda x: None
+        with pytest.warns(DeprecationWarning, match="display_pygraphviz is deprecated"):
+            with open(path_name, "wb") as fh:
+                nx.nx_agraph.display_pygraphviz(A, fh, prog="dot")

venv/Lib/site-packages/networkx/drawing/tests/test_layout.py

@@ -0,0 +1,406 @@
+"""Unit tests for layout functions."""
+import networkx as nx
+from networkx.testing import almost_equal
+
+import pytest
+
+numpy = pytest.importorskip("numpy")
+test_smoke_empty_graphscipy = pytest.importorskip("scipy")
+
+
+class TestLayout:
+    @classmethod
+    def setup_class(cls):
+        cls.Gi = nx.grid_2d_graph(5, 5)
+        cls.Gs = nx.Graph()
+        nx.add_path(cls.Gs, "abcdef")
+        cls.bigG = nx.grid_2d_graph(25, 25)  # > 500 nodes for sparse
+
+    @staticmethod
+    def collect_node_distances(positions):
+        distances = []
+        prev_val = None
+        for k in positions:
+            if prev_val is not None:
+                diff = positions[k] - prev_val
+                distances.append(numpy.dot(diff, diff) ** 0.5)
+            prev_val = positions[k]
+        return distances
+
+    def test_spring_fixed_without_pos(self):
+        G = nx.path_graph(4)
+        pytest.raises(ValueError, nx.spring_layout, G, fixed=[0])
+        pos = {0: (1, 1), 2: (0, 0)}
+        pytest.raises(ValueError, nx.spring_layout, G, fixed=[0, 1], pos=pos)
+        nx.spring_layout(G, fixed=[0, 2], pos=pos)  # No ValueError
+
+    def test_spring_init_pos(self):
+        # Tests GH #2448
+        import math
+
+        G = nx.Graph()
+        G.add_edges_from([(0, 1), (1, 2), (2, 0), (2, 3)])
+
+        init_pos = {0: (0.0, 0.0)}
+        fixed_pos = [0]
+        pos = nx.fruchterman_reingold_layout(G, pos=init_pos, fixed=fixed_pos)
+        has_nan = any(math.isnan(c) for coords in pos.values() for c in coords)
+        assert not has_nan, "values should not be nan"
+
+    def test_smoke_empty_graph(self):
+        G = []
+        nx.random_layout(G)
+        nx.circular_layout(G)
+        nx.planar_layout(G)
+        nx.spring_layout(G)
+        nx.fruchterman_reingold_layout(G)
+        nx.spectral_layout(G)
+        nx.shell_layout(G)
+        nx.bipartite_layout(G, G)
+        nx.spiral_layout(G)
+        nx.multipartite_layout(G)
+        nx.kamada_kawai_layout(G)
+
+    def test_smoke_int(self):
+        G = self.Gi
+        nx.random_layout(G)
+        nx.circular_layout(G)
+        nx.planar_layout(G)
+        nx.spring_layout(G)
+        nx.fruchterman_reingold_layout(G)
+        nx.fruchterman_reingold_layout(self.bigG)
+        nx.spectral_layout(G)
+        nx.spectral_layout(G.to_directed())
+        nx.spectral_layout(self.bigG)
+        nx.spectral_layout(self.bigG.to_directed())
+        nx.shell_layout(G)
+        nx.spiral_layout(G)
+        nx.kamada_kawai_layout(G)
+        nx.kamada_kawai_layout(G, dim=1)
+        nx.kamada_kawai_layout(G, dim=3)
+
+    def test_smoke_string(self):
+        G = self.Gs
+        nx.random_layout(G)
+        nx.circular_layout(G)
+        nx.planar_layout(G)
+        nx.spring_layout(G)
+        nx.fruchterman_reingold_layout(G)
+        nx.spectral_layout(G)
+        nx.shell_layout(G)
+        nx.spiral_layout(G)
+        nx.kamada_kawai_layout(G)
+        nx.kamada_kawai_layout(G, dim=1)
+        nx.kamada_kawai_layout(G, dim=3)
+
+    def check_scale_and_center(self, pos, scale, center):
+        center = numpy.array(center)
+        low = center - scale
+        hi = center + scale
+        vpos = numpy.array(list(pos.values()))
+        length = vpos.max(0) - vpos.min(0)
+        assert (length <= 2 * scale).all()
+        assert (vpos >= low).all()
+        assert (vpos <= hi).all()
+
+    def test_scale_and_center_arg(self):
+        sc = self.check_scale_and_center
+        c = (4, 5)
+        G = nx.complete_graph(9)
+        G.add_node(9)
+        sc(nx.random_layout(G, center=c), scale=0.5, center=(4.5, 5.5))
+        # rest can have 2*scale length: [-scale, scale]
+        sc(nx.spring_layout(G, scale=2, center=c), scale=2, center=c)
+        sc(nx.spectral_layout(G, scale=2, center=c), scale=2, center=c)
+        sc(nx.circular_layout(G, scale=2, center=c), scale=2, center=c)
+        sc(nx.shell_layout(G, scale=2, center=c), scale=2, center=c)
+        sc(nx.spiral_layout(G, scale=2, center=c), scale=2, center=c)
+        sc(nx.kamada_kawai_layout(G, scale=2, center=c), scale=2, center=c)
+
+        c = (2, 3, 5)
+        sc(nx.kamada_kawai_layout(G, dim=3, scale=2, center=c), scale=2, center=c)
+
+    def test_planar_layout_non_planar_input(self):
+        G = nx.complete_graph(9)
+        pytest.raises(nx.NetworkXException, nx.planar_layout, G)
+
+    def test_smoke_planar_layout_embedding_input(self):
+        embedding = nx.PlanarEmbedding()
+        embedding.set_data({0: [1, 2], 1: [0, 2], 2: [0, 1]})
+        nx.planar_layout(embedding)
+
+    def test_default_scale_and_center(self):
+        sc = self.check_scale_and_center
+        c = (0, 0)
+        G = nx.complete_graph(9)
+        G.add_node(9)
+        sc(nx.random_layout(G), scale=0.5, center=(0.5, 0.5))
+        sc(nx.spring_layout(G), scale=1, center=c)
+        sc(nx.spectral_layout(G), scale=1, center=c)
+        sc(nx.circular_layout(G), scale=1, center=c)
+        sc(nx.shell_layout(G), scale=1, center=c)
+        sc(nx.spiral_layout(G), scale=1, center=c)
+        sc(nx.kamada_kawai_layout(G), scale=1, center=c)
+
+        c = (0, 0, 0)
+        sc(nx.kamada_kawai_layout(G, dim=3), scale=1, center=c)
+
+    def test_circular_planar_and_shell_dim_error(self):
+        G = nx.path_graph(4)
+        pytest.raises(ValueError, nx.circular_layout, G, dim=1)
+        pytest.raises(ValueError, nx.shell_layout, G, dim=1)
+        pytest.raises(ValueError, nx.shell_layout, G, dim=3)
+        pytest.raises(ValueError, nx.planar_layout, G, dim=1)
+        pytest.raises(ValueError, nx.planar_layout, G, dim=3)
+
+    def test_adjacency_interface_numpy(self):
+        A = nx.to_numpy_array(self.Gs)
+        pos = nx.drawing.layout._fruchterman_reingold(A)
+        assert pos.shape == (6, 2)
+        pos = nx.drawing.layout._fruchterman_reingold(A, dim=3)
+        assert pos.shape == (6, 3)
+        pos = nx.drawing.layout._sparse_fruchterman_reingold(A)
+        assert pos.shape == (6, 2)
+
+    def test_adjacency_interface_scipy(self):
+        A = nx.to_scipy_sparse_matrix(self.Gs, dtype="d")
+        pos = nx.drawing.layout._sparse_fruchterman_reingold(A)
+        assert pos.shape == (6, 2)
+        pos = nx.drawing.layout._sparse_spectral(A)
+        assert pos.shape == (6, 2)
+        pos = nx.drawing.layout._sparse_fruchterman_reingold(A, dim=3)
+        assert pos.shape == (6, 3)
+
+    def test_single_nodes(self):
+        G = nx.path_graph(1)
+        vpos = nx.shell_layout(G)
+        assert not vpos[0].any()
+        G = nx.path_graph(4)
+        vpos = nx.shell_layout(G, [[0], [1, 2], [3]])
+        assert not vpos[0].any()
+        assert vpos[3].any()  # ensure node 3 not at origin (#3188)
+        assert numpy.linalg.norm(vpos[3]) <= 1  # ensure node 3 fits (#3753)
+        vpos = nx.shell_layout(G, [[0], [1, 2], [3]], rotate=0)
+        assert numpy.linalg.norm(vpos[3]) <= 1  # ensure node 3 fits (#3753)
+
+    def test_smoke_initial_pos_fruchterman_reingold(self):
+        pos = nx.circular_layout(self.Gi)
+        npos = nx.fruchterman_reingold_layout(self.Gi, pos=pos)
+
+    def test_fixed_node_fruchterman_reingold(self):
+        # Dense version (numpy based)
+        pos = nx.circular_layout(self.Gi)
+        npos = nx.spring_layout(self.Gi, pos=pos, fixed=[(0, 0)])
+        assert tuple(pos[(0, 0)]) == tuple(npos[(0, 0)])
+        # Sparse version (scipy based)
+        pos = nx.circular_layout(self.bigG)
+        npos = nx.spring_layout(self.bigG, pos=pos, fixed=[(0, 0)])
+        for axis in range(2):
+            assert almost_equal(pos[(0, 0)][axis], npos[(0, 0)][axis])
+
+    def test_center_parameter(self):
+        G = nx.path_graph(1)
+        nx.random_layout(G, center=(1, 1))
+        vpos = nx.circular_layout(G, center=(1, 1))
+        assert tuple(vpos[0]) == (1, 1)
+        vpos = nx.planar_layout(G, center=(1, 1))
+        assert tuple(vpos[0]) == (1, 1)
+        vpos = nx.spring_layout(G, center=(1, 1))
+        assert tuple(vpos[0]) == (1, 1)
+        vpos = nx.fruchterman_reingold_layout(G, center=(1, 1))
+        assert tuple(vpos[0]) == (1, 1)
+        vpos = nx.spectral_layout(G, center=(1, 1))
+        assert tuple(vpos[0]) == (1, 1)
+        vpos = nx.shell_layout(G, center=(1, 1))
+        assert tuple(vpos[0]) == (1, 1)
+        vpos = nx.spiral_layout(G, center=(1, 1))
+        assert tuple(vpos[0]) == (1, 1)
+
+    def test_center_wrong_dimensions(self):
+        G = nx.path_graph(1)
+        assert id(nx.spring_layout) == id(nx.fruchterman_reingold_layout)
+        pytest.raises(ValueError, nx.random_layout, G, center=(1, 1, 1))
+        pytest.raises(ValueError, nx.circular_layout, G, center=(1, 1, 1))
+        pytest.raises(ValueError, nx.planar_layout, G, center=(1, 1, 1))
+        pytest.raises(ValueError, nx.spring_layout, G, center=(1, 1, 1))
+        pytest.raises(ValueError, nx.spring_layout, G, dim=3, center=(1, 1))
+        pytest.raises(ValueError, nx.spectral_layout, G, center=(1, 1, 1))
+        pytest.raises(ValueError, nx.spectral_layout, G, dim=3, center=(1, 1))
+        pytest.raises(ValueError, nx.shell_layout, G, center=(1, 1, 1))
+        pytest.raises(ValueError, nx.spiral_layout, G, center=(1, 1, 1))
+        pytest.raises(ValueError, nx.kamada_kawai_layout, G, center=(1, 1, 1))
+
+    def test_empty_graph(self):
+        G = nx.empty_graph()
+        vpos = nx.random_layout(G, center=(1, 1))
+        assert vpos == {}
+        vpos = nx.circular_layout(G, center=(1, 1))
+        assert vpos == {}
+        vpos = nx.planar_layout(G, center=(1, 1))
+        assert vpos == {}
+        vpos = nx.bipartite_layout(G, G)
+        assert vpos == {}
+        vpos = nx.spring_layout(G, center=(1, 1))
+        assert vpos == {}
+        vpos = nx.fruchterman_reingold_layout(G, center=(1, 1))
+        assert vpos == {}
+        vpos = nx.spectral_layout(G, center=(1, 1))
+        assert vpos == {}
+        vpos = nx.shell_layout(G, center=(1, 1))
+        assert vpos == {}
+        vpos = nx.spiral_layout(G, center=(1, 1))
+        assert vpos == {}
+        vpos = nx.multipartite_layout(G, center=(1, 1))
+        assert vpos == {}
+        vpos = nx.kamada_kawai_layout(G, center=(1, 1))
+        assert vpos == {}
+
+    def test_bipartite_layout(self):
+        G = nx.complete_bipartite_graph(3, 5)
+        top, bottom = nx.bipartite.sets(G)
+
+        vpos = nx.bipartite_layout(G, top)
+        assert len(vpos) == len(G)
+
+        top_x = vpos[list(top)[0]][0]
+        bottom_x = vpos[list(bottom)[0]][0]
+        for node in top:
+            assert vpos[node][0] == top_x
+        for node in bottom:
+            assert vpos[node][0] == bottom_x
+
+        vpos = nx.bipartite_layout(
+            G, top, align="horizontal", center=(2, 2), scale=2, aspect_ratio=1
+        )
+        assert len(vpos) == len(G)
+
+        top_y = vpos[list(top)[0]][1]
+        bottom_y = vpos[list(bottom)[0]][1]
+        for node in top:
+            assert vpos[node][1] == top_y
+        for node in bottom:
+            assert vpos[node][1] == bottom_y
+
+        pytest.raises(ValueError, nx.bipartite_layout, G, top, align="foo")
+
+    def test_multipartite_layout(self):
+        sizes = (0, 5, 7, 2, 8)
+        G = nx.complete_multipartite_graph(*sizes)
+
+        vpos = nx.multipartite_layout(G)
+        assert len(vpos) == len(G)
+
+        start = 0
+        for n in sizes:
+            end = start + n
+            assert all(vpos[start][0] == vpos[i][0] for i in range(start + 1, end))
+            start += n
+
+        vpos = nx.multipartite_layout(G, align="horizontal", scale=2, center=(2, 2))
+        assert len(vpos) == len(G)
+
+        start = 0
+        for n in sizes:
+            end = start + n
+            assert all(vpos[start][1] == vpos[i][1] for i in range(start + 1, end))
+            start += n
+
+        pytest.raises(ValueError, nx.multipartite_layout, G, align="foo")
+
+    def test_kamada_kawai_costfn_1d(self):
+        costfn = nx.drawing.layout._kamada_kawai_costfn
+
+        pos = numpy.array([4.0, 7.0])
+        invdist = 1 / numpy.array([[0.1, 2.0], [2.0, 0.3]])
+
+        cost, grad = costfn(pos, numpy, invdist, meanweight=0, dim=1)
+
+        assert almost_equal(cost, ((3 / 2.0 - 1) ** 2))
+        assert almost_equal(grad[0], -0.5)
+        assert almost_equal(grad[1], 0.5)
+
+    def check_kamada_kawai_costfn(self, pos, invdist, meanwt, dim):
+        costfn = nx.drawing.layout._kamada_kawai_costfn
+
+        cost, grad = costfn(pos.ravel(), numpy, invdist, meanweight=meanwt, dim=dim)
+
+        expected_cost = 0.5 * meanwt * numpy.sum(numpy.sum(pos, axis=0) ** 2)
+        for i in range(pos.shape[0]):
+            for j in range(i + 1, pos.shape[0]):
+                diff = numpy.linalg.norm(pos[i] - pos[j])
+                expected_cost += (diff * invdist[i][j] - 1.0) ** 2
+
+        assert almost_equal(cost, expected_cost)
+
+        dx = 1e-4
+        for nd in range(pos.shape[0]):
+            for dm in range(pos.shape[1]):
+                idx = nd * pos.shape[1] + dm
+                pos0 = pos.flatten()
+
+                pos0[idx] += dx
+                cplus = costfn(
+                    pos0, numpy, invdist, meanweight=meanwt, dim=pos.shape[1]
+                )[0]
+
+                pos0[idx] -= 2 * dx
+                cminus = costfn(
+                    pos0, numpy, invdist, meanweight=meanwt, dim=pos.shape[1]
+                )[0]
+
+                assert almost_equal(grad[idx], (cplus - cminus) / (2 * dx), places=5)
+
+    def test_kamada_kawai_costfn(self):
+        invdist = 1 / numpy.array([[0.1, 2.1, 1.7], [2.1, 0.2, 0.6], [1.7, 0.6, 0.3]])
+        meanwt = 0.3
+
+        # 2d
+        pos = numpy.array([[1.3, -3.2], [2.7, -0.3], [5.1, 2.5]])
+
+        self.check_kamada_kawai_costfn(pos, invdist, meanwt, 2)
+
+        # 3d
+        pos = numpy.array([[0.9, 8.6, -8.7], [-10, -0.5, -7.1], [9.1, -8.1, 1.6]])
+
+        self.check_kamada_kawai_costfn(pos, invdist, meanwt, 3)
+
+    def test_spiral_layout(self):
+
+        G = self.Gs
+
+        # a lower value of resolution should result in a more compact layout
+        # intuitively, the total distance from the start and end nodes
+        # via each node in between (transiting through each) will be less,
+        # assuming rescaling does not occur on the computed node positions
+        pos_standard = nx.spiral_layout(G, resolution=0.35)
+        pos_tighter = nx.spiral_layout(G, resolution=0.34)
+        distances = self.collect_node_distances(pos_standard)
+        distances_tighter = self.collect_node_distances(pos_tighter)
+        assert sum(distances) > sum(distances_tighter)
+
+        # return near-equidistant points after the first value if set to true
+        pos_equidistant = nx.spiral_layout(G, equidistant=True)
+        distances_equidistant = self.collect_node_distances(pos_equidistant)
+        for d in range(1, len(distances_equidistant) - 1):
+            # test similarity to two decimal places
+            assert almost_equal(
+                distances_equidistant[d], distances_equidistant[d + 1], 2
+            )
+
+    def test_rescale_layout_dict(self):
+        G = nx.empty_graph()
+        vpos = nx.random_layout(G, center=(1, 1))
+        assert nx.rescale_layout_dict(vpos) == {}
+
+        G = nx.empty_graph(2)
+        vpos = {0: (0.0, 0.0), 1: (1.0, 1.0)}
+        s_vpos = nx.rescale_layout_dict(vpos)
+        norm = numpy.linalg.norm
+        assert norm([sum(x) for x in zip(*s_vpos.values())]) < 1e-6
+
+        G = nx.empty_graph(3)
+        vpos = {0: (0, 0), 1: (1, 1), 2: (0.5, 0.5)}
+        s_vpos = nx.rescale_layout_dict(vpos)
+        assert s_vpos == {0: (-1, -1), 1: (1, 1), 2: (0, 0)}
+        s_vpos = nx.rescale_layout_dict(vpos, scale=2)
+        assert s_vpos == {0: (-2, -2), 1: (2, 2), 2: (0, 0)}

venv/Lib/site-packages/networkx/drawing/tests/test_pydot.py

@@ -0,0 +1,94 @@
+"""Unit tests for pydot drawing functions."""
+from io import StringIO
+import tempfile
+import networkx as nx
+from networkx.testing import assert_graphs_equal
+
+import pytest
+
+pydot = pytest.importorskip("pydot")
+
+
+class TestPydot:
+    def pydot_checks(self, G, prog):
+        """
+        Validate :mod:`pydot`-based usage of the passed NetworkX graph with the
+        passed basename of an external GraphViz command (e.g., `dot`, `neato`).
+        """
+
+        # Set the name of this graph to... "G". Failing to do so will
+        # subsequently trip an assertion expecting this name.
+        G.graph["name"] = "G"
+
+        # Add arbitrary nodes and edges to the passed empty graph.
+        G.add_edges_from([("A", "B"), ("A", "C"), ("B", "C"), ("A", "D")])
+        G.add_node("E")
+
+        # Validate layout of this graph with the passed GraphViz command.
+        graph_layout = nx.nx_pydot.pydot_layout(G, prog=prog)
+        assert isinstance(graph_layout, dict)
+
+        # Convert this graph into a "pydot.Dot" instance.
+        P = nx.nx_pydot.to_pydot(G)
+
+        # Convert this "pydot.Dot" instance back into a graph of the same type.
+        G2 = G.__class__(nx.nx_pydot.from_pydot(P))
+
+        # Validate the original and resulting graphs to be the same.
+        assert_graphs_equal(G, G2)
+
+        # Serialize this "pydot.Dot" instance to a temporary file in dot format
+        fname = tempfile.mktemp()
+        P.write_raw(fname)
+
+        # Deserialize a list of new "pydot.Dot" instances back from this file.
+        Pin_list = pydot.graph_from_dot_file(path=fname, encoding="utf-8")
+
+        # Validate this file to contain only one graph.
+        assert len(Pin_list) == 1
+
+        # The single "pydot.Dot" instance deserialized from this file.
+        Pin = Pin_list[0]
+
+        # Sorted list of all nodes in the original "pydot.Dot" instance.
+        n1 = sorted([p.get_name() for p in P.get_node_list()])
+
+        # Sorted list of all nodes in the deserialized "pydot.Dot" instance.
+        n2 = sorted([p.get_name() for p in Pin.get_node_list()])
+
+        # Validate these instances to contain the same nodes.
+        assert n1 == n2
+
+        # Sorted list of all edges in the original "pydot.Dot" instance.
+        e1 = sorted([(e.get_source(), e.get_destination()) for e in P.get_edge_list()])
+
+        # Sorted list of all edges in the original "pydot.Dot" instance.
+        e2 = sorted(
+            [(e.get_source(), e.get_destination()) for e in Pin.get_edge_list()]
+        )
+
+        # Validate these instances to contain the same edges.
+        assert e1 == e2
+
+        # Deserialize a new graph of the same type back from this file.
+        Hin = nx.nx_pydot.read_dot(fname)
+        Hin = G.__class__(Hin)
+
+        # Validate the original and resulting graphs to be the same.
+        assert_graphs_equal(G, Hin)
+
+    def test_undirected(self):
+        self.pydot_checks(nx.Graph(), prog="neato")
+
+    def test_directed(self):
+        self.pydot_checks(nx.DiGraph(), prog="dot")
+
+    def test_read_write(self):
+        G = nx.MultiGraph()
+        G.graph["name"] = "G"
+        G.add_edge("1", "2", key="0")  # read assumes strings
+        fh = StringIO()
+        nx.nx_pydot.write_dot(G, fh)
+        fh.seek(0)
+        H = nx.nx_pydot.read_dot(fh)
+        assert_graphs_equal(G, H)

venv/Lib/site-packages/networkx/drawing/tests/test_pylab.py

@@ -0,0 +1,257 @@
+"""Unit tests for matplotlib drawing functions."""
+import os
+import itertools
+import pytest
+
+mpl = pytest.importorskip("matplotlib")
+mpl.use("PS")
+plt = pytest.importorskip("matplotlib.pyplot")
+plt.rcParams["text.usetex"] = False
+
+import networkx as nx
+
+
+class TestPylab:
+    @classmethod
+    def setup_class(cls):
+        cls.G = nx.barbell_graph(4, 6)
+
+    def test_draw(self):
+        try:
+            functions = [
+                nx.draw_circular,
+                nx.draw_kamada_kawai,
+                nx.draw_planar,
+                nx.draw_random,
+                nx.draw_spectral,
+                nx.draw_spring,
+                nx.draw_shell,
+            ]
+            options = [{"node_color": "black", "node_size": 100, "width": 3}]
+            for function, option in itertools.product(functions, options):
+                function(self.G, **option)
+                plt.savefig("test.ps")
+
+        finally:
+            try:
+                os.unlink("test.ps")
+            except OSError:
+                pass
+
+    def test_draw_shell_nlist(self):
+        try:
+            nlist = [list(range(4)), list(range(4, 10)), list(range(10, 14))]
+            nx.draw_shell(self.G, nlist=nlist)
+            plt.savefig("test.ps")
+        finally:
+            try:
+                os.unlink("test.ps")
+            except OSError:
+                pass
+
+    def test_edge_colormap(self):
+        colors = range(self.G.number_of_edges())
+        nx.draw_spring(
+            self.G, edge_color=colors, width=4, edge_cmap=plt.cm.Blues, with_labels=True
+        )
+        # plt.show()
+
+    def test_arrows(self):
+        nx.draw_spring(self.G.to_directed())
+        # plt.show()
+
+    def test_edge_colors_and_widths(self):
+        pos = nx.circular_layout(self.G)
+        for G in (self.G, self.G.to_directed()):
+            nx.draw_networkx_nodes(G, pos, node_color=[(1.0, 1.0, 0.2, 0.5)])
+            nx.draw_networkx_labels(G, pos)
+            # edge with default color and width
+            nx.draw_networkx_edges(
+                G, pos, edgelist=[(0, 1)], width=None, edge_color=None
+            )
+            # edges with global color strings and widths in lists
+            nx.draw_networkx_edges(
+                G, pos, edgelist=[(0, 2), (0, 3)], width=[3], edge_color=["r"]
+            )
+            # edges with color strings and widths for each edge
+            nx.draw_networkx_edges(
+                G, pos, edgelist=[(0, 2), (0, 3)], width=[1, 3], edge_color=["r", "b"]
+            )
+            # edges with fewer color strings and widths than edges
+            nx.draw_networkx_edges(
+                G,
+                pos,
+                edgelist=[(1, 2), (1, 3), (2, 3), (3, 4)],
+                width=[1, 3],
+                edge_color=["g", "m", "c"],
+            )
+            # edges with more color strings and widths than edges
+            nx.draw_networkx_edges(
+                G,
+                pos,
+                edgelist=[(3, 4)],
+                width=[1, 2, 3, 4],
+                edge_color=["r", "b", "g", "k"],
+            )
+            # with rgb tuple and 3 edges - is interpreted with cmap
+            nx.draw_networkx_edges(
+                G, pos, edgelist=[(4, 5), (5, 6), (6, 7)], edge_color=(1.0, 0.4, 0.3)
+            )
+            # with rgb tuple in list
+            nx.draw_networkx_edges(
+                G, pos, edgelist=[(7, 8), (8, 9)], edge_color=[(0.4, 1.0, 0.0)]
+            )
+            # with rgba tuple and 4 edges - is interpretted with cmap
+            nx.draw_networkx_edges(
+                G,
+                pos,
+                edgelist=[(9, 10), (10, 11), (10, 12), (10, 13)],
+                edge_color=(0.0, 1.0, 1.0, 0.5),
+            )
+            # with rgba tuple in list
+            nx.draw_networkx_edges(
+                G,
+                pos,
+                edgelist=[(9, 10), (10, 11), (10, 12), (10, 13)],
+                edge_color=[(0.0, 1.0, 1.0, 0.5)],
+            )
+            # with color string and global alpha
+            nx.draw_networkx_edges(
+                G, pos, edgelist=[(11, 12), (11, 13)], edge_color="purple", alpha=0.2
+            )
+            # with color string in a list
+            nx.draw_networkx_edges(
+                G, pos, edgelist=[(11, 12), (11, 13)], edge_color=["purple"]
+            )
+            # with single edge and hex color string
+            nx.draw_networkx_edges(G, pos, edgelist=[(12, 13)], edge_color="#1f78b4f0")
+
+            # edge_color as numeric using vmin, vmax
+            nx.draw_networkx_edges(
+                G,
+                pos,
+                edgelist=[(7, 8), (8, 9)],
+                edge_color=[0.2, 0.5],
+                edge_vmin=0.1,
+                edge_vmax=0.6,
+            )
+
+            # plt.show()
+
+    def test_labels_and_colors(self):
+        G = nx.cubical_graph()
+        pos = nx.spring_layout(G)  # positions for all nodes
+        # nodes
+        nx.draw_networkx_nodes(
+            G, pos, nodelist=[0, 1, 2, 3], node_color="r", node_size=500, alpha=0.75
+        )
+        nx.draw_networkx_nodes(
+            G,
+            pos,
+            nodelist=[4, 5, 6, 7],
+            node_color="b",
+            node_size=500,
+            alpha=[0.25, 0.5, 0.75, 1.0],
+        )
+        # edges
+        nx.draw_networkx_edges(G, pos, width=1.0, alpha=0.5)
+        nx.draw_networkx_edges(
+            G,
+            pos,
+            edgelist=[(0, 1), (1, 2), (2, 3), (3, 0)],
+            width=8,
+            alpha=0.5,
+            edge_color="r",
+        )
+        nx.draw_networkx_edges(
+            G,
+            pos,
+            edgelist=[(4, 5), (5, 6), (6, 7), (7, 4)],
+            width=8,
+            alpha=0.5,
+            edge_color="b",
+        )
+        nx.draw_networkx_edges(
+            G,
+            pos,
+            edgelist=[(4, 5), (5, 6), (6, 7), (7, 4)],
+            min_source_margin=0.5,
+            min_target_margin=0.75,
+            width=8,
+            edge_color="b",
+        )
+        # some math labels
+        labels = {}
+        labels[0] = r"$a$"
+        labels[1] = r"$b$"
+        labels[2] = r"$c$"
+        labels[3] = r"$d$"
+        labels[4] = r"$\alpha$"
+        labels[5] = r"$\beta$"
+        labels[6] = r"$\gamma$"
+        labels[7] = r"$\delta$"
+        nx.draw_networkx_labels(G, pos, labels, font_size=16)
+        nx.draw_networkx_edge_labels(G, pos, edge_labels=None, rotate=False)
+        nx.draw_networkx_edge_labels(G, pos, edge_labels={(4, 5): "4-5"})
+        # plt.show()
+
+    def test_axes(self):
+        fig, ax = plt.subplots()
+        nx.draw(self.G, ax=ax)
+
+    def test_empty_graph(self):
+        G = nx.Graph()
+        nx.draw(G)
+
+    def test_draw_empty_nodes_return_values(self):
+        # See Issue #3833
+        from matplotlib.collections import PathCollection, LineCollection
+
+        G = nx.Graph([(1, 2), (2, 3)])
+        DG = nx.DiGraph([(1, 2), (2, 3)])
+        pos = nx.circular_layout(G)
+        assert isinstance(nx.draw_networkx_nodes(G, pos, nodelist=[]), PathCollection)
+        assert isinstance(nx.draw_networkx_nodes(DG, pos, nodelist=[]), PathCollection)
+
+        # drawing empty edges either return an empty LineCollection or empty list.
+        assert isinstance(
+            nx.draw_networkx_edges(G, pos, edgelist=[], arrows=True), LineCollection
+        )
+        assert isinstance(
+            nx.draw_networkx_edges(G, pos, edgelist=[], arrows=False), LineCollection
+        )
+        assert isinstance(
+            nx.draw_networkx_edges(DG, pos, edgelist=[], arrows=False), LineCollection
+        )
+        assert nx.draw_networkx_edges(DG, pos, edgelist=[], arrows=True) == []
+
+    def test_multigraph_edgelist_tuples(self):
+        # See Issue #3295
+        G = nx.path_graph(3, create_using=nx.MultiDiGraph)
+        nx.draw_networkx(G, edgelist=[(0, 1, 0)])
+        nx.draw_networkx(G, edgelist=[(0, 1, 0)], node_size=[10, 20, 0])
+
+    def test_alpha_iter(self):
+        pos = nx.random_layout(self.G)
+        # with fewer alpha elements than nodes
+        plt.subplot(131)
+        nx.draw_networkx_nodes(self.G, pos, alpha=[0.1, 0.2])
+        # with equal alpha elements and nodes
+        num_nodes = len(self.G.nodes)
+        alpha = [x / num_nodes for x in range(num_nodes)]
+        colors = range(num_nodes)
+        plt.subplot(132)
+        nx.draw_networkx_nodes(self.G, pos, node_color=colors, alpha=alpha)
+        # with more alpha elements than nodes
+        alpha.append(1)
+        plt.subplot(133)
+        nx.draw_networkx_nodes(self.G, pos, alpha=alpha)
+
+    def test_error_invalid_kwds(self):
+        with pytest.raises(ValueError, match="Received invalid argument"):
+            nx.draw(self.G, foo="bar")
+
+    def test_np_edgelist(self):
+        # see issue #4129
+        np = pytest.importorskip("numpy")
+        nx.draw_networkx(self.G, edgelist=np.array([(0, 2), (0, 3)]))