pip._internal.resolution.legacy.resolver Namespace Reference

Data Structures
class	Resolver

Functions
None	_check_dist_requires_python (BaseDistribution dist, Tuple[int, int, int] version_info, bool ignore_requires_python=False)

Variables
	logger = logging.getLogger(__name__)
	DiscoveredDependencies = DefaultDict[str, List[InstallRequirement]]

Detailed Description

Dependency Resolution

The dependency resolution in pip is performed as follows:

for top-level requirements:
    a. only one spec allowed per project, regardless of conflicts or not.
       otherwise a "double requirement" exception is raised
    b. they override sub-dependency requirements.
for sub-dependencies
    a. "first found, wins" (where the order is breadth first)

Function Documentation

_check_dist_requires_python()

None _check_dist_requires_python ( BaseDistribution  dist, Tuple[int, int, int]  version_info, bool   ignore_requires_python = False  )

protected

Check whether the given Python version is compatible with a distribution's
"Requires-Python" value.

:param version_info: A 3-tuple of ints representing the Python
    major-minor-micro version to check.
:param ignore_requires_python: Whether to ignore the "Requires-Python"
    value if the given Python version isn't compatible.

:raises UnsupportedPythonVersion: When the given Python version isn't
    compatible.

Definition at line 58 of file resolver.py.

) -> None:
    """
    Check whether the given Python version is compatible with a distribution's
    "Requires-Python" value.
 
    :param version_info: A 3-tuple of ints representing the Python
        major-minor-micro version to check.
    :param ignore_requires_python: Whether to ignore the "Requires-Python"
        value if the given Python version isn't compatible.
 
    :raises UnsupportedPythonVersion: When the given Python version isn't
        compatible.
    """
    # This idiosyncratically converts the SpecifierSet to str and let
    # check_requires_python then parse it again into SpecifierSet. But this
    # is the legacy resolver so I'm just not going to bother refactoring.
    try:
        requires_python = str(dist.requires_python)
    except FileNotFoundError as e:
        raise NoneMetadataError(dist, str(e))
    try:
        is_compatible = check_requires_python(
            requires_python,
            version_info=version_info,
        )
    except specifiers.InvalidSpecifier as exc:
        logger.warning(
            "Package %r has an invalid Requires-Python: %s", dist.raw_name, exc
        )
        return
 
    if is_compatible:
        return
 
    version = ".".join(map(str, version_info))
    if ignore_requires_python:
        logger.debug(
            "Ignoring failed Requires-Python check for package %r: %s not in %r",
            dist.raw_name,
            version,
            requires_python,
        )
        return
 
    raise UnsupportedPythonVersion(
        "Package {!r} requires a different Python: {} not in {!r}".format(
            dist.raw_name, version, requires_python
        )
    )
 
 

References i.

Referenced by Resolver._resolve_one().

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Variable Documentation

DiscoveredDependencies

DiscoveredDependencies = DefaultDict[str, List[InstallRequirement]]

Definition at line 55 of file resolver.py.

logger

logger = logging.getLogger(__name__)

Definition at line 53 of file resolver.py.