Fixed database typo and removed unnecessary class identifier.

venv/Lib/site-packages/matplotlib/tests/test_animation.py

@@ -0,0 +1,274 @@
+import os
+from pathlib import Path
+import subprocess
+import sys
+import weakref
+
+import numpy as np
+import pytest
+
+import matplotlib as mpl
+from matplotlib import pyplot as plt
+from matplotlib import animation
+
+
+class NullMovieWriter(animation.AbstractMovieWriter):
+    """
+    A minimal MovieWriter.  It doesn't actually write anything.
+    It just saves the arguments that were given to the setup() and
+    grab_frame() methods as attributes, and counts how many times
+    grab_frame() is called.
+
+    This class doesn't have an __init__ method with the appropriate
+    signature, and it doesn't define an isAvailable() method, so
+    it cannot be added to the 'writers' registry.
+    """
+
+    def setup(self, fig, outfile, dpi, *args):
+        self.fig = fig
+        self.outfile = outfile
+        self.dpi = dpi
+        self.args = args
+        self._count = 0
+
+    def grab_frame(self, **savefig_kwargs):
+        self.savefig_kwargs = savefig_kwargs
+        self._count += 1
+
+    def finish(self):
+        pass
+
+
+def make_animation(**kwargs):
+    fig, ax = plt.subplots()
+    line, = ax.plot([])
+
+    def init():
+        pass
+
+    def animate(i):
+        line.set_data([0, 1], [0, i])
+        return line,
+
+    return animation.FuncAnimation(fig, animate, **kwargs)
+
+
+def test_null_movie_writer():
+    # Test running an animation with NullMovieWriter.
+
+    num_frames = 5
+    anim = make_animation(frames=num_frames)
+
+    filename = "unused.null"
+    dpi = 50
+    savefig_kwargs = dict(foo=0)
+    writer = NullMovieWriter()
+
+    anim.save(filename, dpi=dpi, writer=writer,
+              savefig_kwargs=savefig_kwargs)
+
+    assert writer.fig == plt.figure(1)  # The figure used by make_animation.
+    assert writer.outfile == filename
+    assert writer.dpi == dpi
+    assert writer.args == ()
+    assert writer.savefig_kwargs == savefig_kwargs
+    assert writer._count == num_frames
+
+
+def test_movie_writer_dpi_default():
+    class DummyMovieWriter(animation.MovieWriter):
+        def _run(self):
+            pass
+
+    # Test setting up movie writer with figure.dpi default.
+    fig = plt.figure()
+
+    filename = "unused.null"
+    fps = 5
+    codec = "unused"
+    bitrate = 1
+    extra_args = ["unused"]
+
+    writer = DummyMovieWriter(fps, codec, bitrate, extra_args)
+    writer.setup(fig, filename)
+    assert writer.dpi == fig.dpi
+
+
+@animation.writers.register('null')
+class RegisteredNullMovieWriter(NullMovieWriter):
+
+    # To be able to add NullMovieWriter to the 'writers' registry,
+    # we must define an __init__ method with a specific signature,
+    # and we must define the class method isAvailable().
+    # (These methods are not actually required to use an instance
+    # of this class as the 'writer' argument of Animation.save().)
+
+    def __init__(self, fps=None, codec=None, bitrate=None,
+                 extra_args=None, metadata=None):
+        pass
+
+    @classmethod
+    def isAvailable(cls):
+        return True
+
+
+WRITER_OUTPUT = [
+    ('ffmpeg', 'movie.mp4'),
+    ('ffmpeg_file', 'movie.mp4'),
+    ('avconv', 'movie.mp4'),
+    ('avconv_file', 'movie.mp4'),
+    ('imagemagick', 'movie.gif'),
+    ('imagemagick_file', 'movie.gif'),
+    ('pillow', 'movie.gif'),
+    ('html', 'movie.html'),
+    ('null', 'movie.null')
+]
+WRITER_OUTPUT += [
+    (writer, Path(output)) for writer, output in WRITER_OUTPUT]
+
+
+# Smoke test for saving animations.  In the future, we should probably
+# design more sophisticated tests which compare resulting frames a-la
+# matplotlib.testing.image_comparison
+@pytest.mark.parametrize('writer, output', WRITER_OUTPUT)
+def test_save_animation_smoketest(tmpdir, writer, output):
+    if not animation.writers.is_available(writer):
+        pytest.skip("writer '%s' not available on this system" % writer)
+    fig, ax = plt.subplots()
+    line, = ax.plot([], [])
+
+    ax.set_xlim(0, 10)
+    ax.set_ylim(-1, 1)
+
+    dpi = None
+    codec = None
+    if writer == 'ffmpeg':
+        # Issue #8253
+        fig.set_size_inches((10.85, 9.21))
+        dpi = 100.
+        codec = 'h264'
+
+    def init():
+        line.set_data([], [])
+        return line,
+
+    def animate(i):
+        x = np.linspace(0, 10, 100)
+        y = np.sin(x + i)
+        line.set_data(x, y)
+        return line,
+
+    # Use temporary directory for the file-based writers, which produce a file
+    # per frame with known names.
+    with tmpdir.as_cwd():
+        anim = animation.FuncAnimation(fig, animate, init_func=init, frames=5)
+        anim.save(output, fps=30, writer=writer, bitrate=500, dpi=dpi,
+                  codec=codec)
+
+
+def test_no_length_frames():
+    (make_animation(frames=iter(range(5)))
+     .save('unused.null', writer=NullMovieWriter()))
+
+
+def test_movie_writer_registry():
+    assert len(animation.writers._registered) > 0
+    mpl.rcParams['animation.ffmpeg_path'] = "not_available_ever_xxxx"
+    assert not animation.writers.is_available("ffmpeg")
+    # something guaranteed to be available in path and exits immediately
+    bin = "true" if sys.platform != 'win32' else "where"
+    mpl.rcParams['animation.ffmpeg_path'] = bin
+    assert animation.writers.is_available("ffmpeg")
+
+
+@pytest.mark.parametrize(
+    "method_name",
+    [pytest.param("to_html5_video", marks=pytest.mark.skipif(
+        not animation.writers.is_available(mpl.rcParams["animation.writer"]),
+        reason="animation writer not installed")),
+     "to_jshtml"])
+def test_embed_limit(method_name, caplog, tmpdir):
+    caplog.set_level("WARNING")
+    with tmpdir.as_cwd():
+        with mpl.rc_context({"animation.embed_limit": 1e-6}):  # ~1 byte.
+            getattr(make_animation(frames=1), method_name)()
+    assert len(caplog.records) == 1
+    record, = caplog.records
+    assert (record.name == "matplotlib.animation"
+            and record.levelname == "WARNING")
+
+
+@pytest.mark.parametrize(
+    "method_name",
+    [pytest.param("to_html5_video", marks=pytest.mark.skipif(
+        not animation.writers.is_available(mpl.rcParams["animation.writer"]),
+        reason="animation writer not installed")),
+     "to_jshtml"])
+def test_cleanup_temporaries(method_name, tmpdir):
+    with tmpdir.as_cwd():
+        getattr(make_animation(frames=1), method_name)()
+        assert list(Path(str(tmpdir)).iterdir()) == []
+
+
+@pytest.mark.skipif(os.name != "posix", reason="requires a POSIX OS")
+def test_failing_ffmpeg(tmpdir, monkeypatch):
+    """
+    Test that we correctly raise a CalledProcessError when ffmpeg fails.
+
+    To do so, mock ffmpeg using a simple executable shell script that
+    succeeds when called with no arguments (so that it gets registered by
+    `isAvailable`), but fails otherwise, and add it to the $PATH.
+    """
+    with tmpdir.as_cwd():
+        monkeypatch.setenv("PATH", ".:" + os.environ["PATH"])
+        exe_path = Path(str(tmpdir), "ffmpeg")
+        exe_path.write_text("#!/bin/sh\n"
+                            "[[ $@ -eq 0 ]]\n")
+        os.chmod(str(exe_path), 0o755)
+        with pytest.raises(subprocess.CalledProcessError):
+            make_animation().save("test.mpeg")
+
+
+@pytest.mark.parametrize("cache_frame_data", [False, True])
+def test_funcanimation_cache_frame_data(cache_frame_data):
+    fig, ax = plt.subplots()
+    line, = ax.plot([], [])
+
+    class Frame(dict):
+        # this subclassing enables to use weakref.ref()
+        pass
+
+    def init():
+        line.set_data([], [])
+        return line,
+
+    def animate(frame):
+        line.set_data(frame['x'], frame['y'])
+        return line,
+
+    frames_generated = []
+
+    def frames_generator():
+        for _ in range(5):
+            x = np.linspace(0, 10, 100)
+            y = np.random.rand(100)
+
+            frame = Frame(x=x, y=y)
+
+            # collect weak references to frames
+            # to validate their references later
+            frames_generated.append(weakref.ref(frame))
+
+            yield frame
+
+    anim = animation.FuncAnimation(fig, animate, init_func=init,
+                                   frames=frames_generator,
+                                   cache_frame_data=cache_frame_data)
+
+    writer = NullMovieWriter()
+    anim.save('unused.null', writer=writer)
+    assert len(frames_generated) == 5
+    for f in frames_generated:
+        # If cache_frame_data is True, then the weakref should be alive;
+        # if cache_frame_data is False, then the weakref should be dead (None).
+        assert (f() is None) != cache_frame_data