| 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()) |
