Created starter files for the project.

venv/Lib/site-packages/pip/_internal/resolution/resolvelib/requirements.py

@@ -0,0 +1,137 @@
+from pip._vendor.packaging.utils import canonicalize_name
+
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+
+from .base import Requirement, format_name
+
+if MYPY_CHECK_RUNNING:
+    from pip._vendor.packaging.specifiers import SpecifierSet
+
+    from pip._internal.req.req_install import InstallRequirement
+
+    from .base import Candidate, CandidateLookup
+
+
+class ExplicitRequirement(Requirement):
+    def __init__(self, candidate):
+        # type: (Candidate) -> None
+        self.candidate = candidate
+
+    def __repr__(self):
+        # type: () -> str
+        return "{class_name}({candidate!r})".format(
+            class_name=self.__class__.__name__,
+            candidate=self.candidate,
+        )
+
+    @property
+    def name(self):
+        # type: () -> str
+        # No need to canonicalise - the candidate did this
+        return self.candidate.name
+
+    def format_for_error(self):
+        # type: () -> str
+        return self.candidate.format_for_error()
+
+    def get_candidate_lookup(self):
+        # type: () -> CandidateLookup
+        return self.candidate, None
+
+    def is_satisfied_by(self, candidate):
+        # type: (Candidate) -> bool
+        return candidate == self.candidate
+
+
+class SpecifierRequirement(Requirement):
+    def __init__(self, ireq):
+        # type: (InstallRequirement) -> None
+        assert ireq.link is None, "This is a link, not a specifier"
+        self._ireq = ireq
+        self._extras = frozenset(ireq.extras)
+
+    def __str__(self):
+        # type: () -> str
+        return str(self._ireq.req)
+
+    def __repr__(self):
+        # type: () -> str
+        return "{class_name}({requirement!r})".format(
+            class_name=self.__class__.__name__,
+            requirement=str(self._ireq.req),
+        )
+
+    @property
+    def name(self):
+        # type: () -> str
+        canonical_name = canonicalize_name(self._ireq.req.name)
+        return format_name(canonical_name, self._extras)
+
+    def format_for_error(self):
+        # type: () -> str
+
+        # Convert comma-separated specifiers into "A, B, ..., F and G"
+        # This makes the specifier a bit more "human readable", without
+        # risking a change in meaning. (Hopefully! Not all edge cases have
+        # been checked)
+        parts = [s.strip() for s in str(self).split(",")]
+        if len(parts) == 0:
+            return ""
+        elif len(parts) == 1:
+            return parts[0]
+
+        return ", ".join(parts[:-1]) + " and " + parts[-1]
+
+    def get_candidate_lookup(self):
+        # type: () -> CandidateLookup
+        return None, self._ireq
+
+    def is_satisfied_by(self, candidate):
+        # type: (Candidate) -> bool
+        assert candidate.name == self.name, \
+            "Internal issue: Candidate is not for this requirement " \
+            " {} vs {}".format(candidate.name, self.name)
+        # We can safely always allow prereleases here since PackageFinder
+        # already implements the prerelease logic, and would have filtered out
+        # prerelease candidates if the user does not expect them.
+        spec = self._ireq.req.specifier
+        return spec.contains(candidate.version, prereleases=True)
+
+
+class RequiresPythonRequirement(Requirement):
+    """A requirement representing Requires-Python metadata.
+    """
+    def __init__(self, specifier, match):
+        # type: (SpecifierSet, Candidate) -> None
+        self.specifier = specifier
+        self._candidate = match
+
+    def __repr__(self):
+        # type: () -> str
+        return "{class_name}({specifier!r})".format(
+            class_name=self.__class__.__name__,
+            specifier=str(self.specifier),
+        )
+
+    @property
+    def name(self):
+        # type: () -> str
+        return self._candidate.name
+
+    def format_for_error(self):
+        # type: () -> str
+        return "Python " + str(self.specifier)
+
+    def get_candidate_lookup(self):
+        # type: () -> CandidateLookup
+        if self.specifier.contains(self._candidate.version, prereleases=True):
+            return self._candidate, None
+        return None, None
+
+    def is_satisfied_by(self, candidate):
+        # type: (Candidate) -> bool
+        assert candidate.name == self._candidate.name, "Not Python candidate"
+        # We can safely always allow prereleases here since PackageFinder
+        # already implements the prerelease logic, and would have filtered out
+        # prerelease candidates if the user does not expect them.
+        return self.specifier.contains(candidate.version, prereleases=True)