Class Prepared

Lib/importlib/metadata/__init__.py:927–980

A prepared search query for metadata on a possibly-named package. Pre-calculates the normalization to prevent repeated operations. >>> none = Prepared(None) >>> none.normalized >>> none.legacy_normalized >>> bool(none) False >>> sample = Prepared('Sample__Pkg-name.

class Prepared:
    """
    A prepared search query for metadata on a possibly-named package.

    Pre-calculates the normalization to prevent repeated operations.

    >>> none = Prepared(None)
    >>> none.normalized
    >>> none.legacy_normalized
    >>> bool(none)
    False
    >>> sample = Prepared('Sample__Pkg-name.foo')
    >>> sample.normalized
    'sample_pkg_name_foo'
    >>> sample.legacy_normalized
    'sample__pkg_name.foo'
    >>> bool(sample)
    True
    """

    normalized = None
    legacy_normalized = None

    def __init__(self, name: str | None):
        self.name = name
        if name is None:
            return
        self.normalized = self.normalize(name)
        self.legacy_normalized = self.legacy_normalize(name)

    @staticmethod
    def normalize(name):
        """
        PEP 503 normalization plus dashes as underscores.

        Specifically avoids ``re.sub`` as prescribed for performance
        benefits (see python/cpython#143658).
        """
        value = name.lower().replace("-", "_").replace(".", "_")
        # Condense repeats
        while "__" in value:
            value = value.replace("__", "_")
        return value

    @staticmethod
    def legacy_normalize(name):
        """
        Normalize the package name as found in the convention in
        older packaging tools versions and specs.
        """
        return name.lower().replace('-', '_')

    def __bool__(self):
        return bool(self.name)


class MetadataPathFinder(DistributionFinder):