diff options
Diffstat (limited to 'third_party/python/pip/pip/_internal/utils/packaging.py')
-rw-r--r-- | third_party/python/pip/pip/_internal/utils/packaging.py | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/third_party/python/pip/pip/_internal/utils/packaging.py b/third_party/python/pip/pip/_internal/utils/packaging.py new file mode 100644 index 0000000000..b9f6af4d17 --- /dev/null +++ b/third_party/python/pip/pip/_internal/utils/packaging.py @@ -0,0 +1,57 @@ +import functools +import logging +import re +from typing import NewType, Optional, Tuple, cast + +from pip._vendor.packaging import specifiers, version +from pip._vendor.packaging.requirements import Requirement + +NormalizedExtra = NewType("NormalizedExtra", str) + +logger = logging.getLogger(__name__) + + +def check_requires_python( + requires_python: Optional[str], version_info: Tuple[int, ...] +) -> bool: + """ + Check if the given Python version matches a "Requires-Python" specifier. + + :param version_info: A 3-tuple of ints representing a Python + major-minor-micro version to check (e.g. `sys.version_info[:3]`). + + :return: `True` if the given Python version satisfies the requirement. + Otherwise, return `False`. + + :raises InvalidSpecifier: If `requires_python` has an invalid format. + """ + if requires_python is None: + # The package provides no information + return True + requires_python_specifier = specifiers.SpecifierSet(requires_python) + + python_version = version.parse(".".join(map(str, version_info))) + return python_version in requires_python_specifier + + +@functools.lru_cache(maxsize=512) +def get_requirement(req_string: str) -> Requirement: + """Construct a packaging.Requirement object with caching""" + # Parsing requirement strings is expensive, and is also expected to happen + # with a low diversity of different arguments (at least relative the number + # constructed). This method adds a cache to requirement object creation to + # minimize repeated parsing of the same string to construct equivalent + # Requirement objects. + return Requirement(req_string) + + +def safe_extra(extra: str) -> NormalizedExtra: + """Convert an arbitrary string to a standard 'extra' name + + Any runs of non-alphanumeric characters are replaced with a single '_', + and the result is always lowercased. + + This function is duplicated from ``pkg_resources``. Note that this is not + the same to either ``canonicalize_name`` or ``_egg_link_name``. + """ + return cast(NormalizedExtra, re.sub("[^A-Za-z0-9.-]+", "_", extra).lower()) |