| # This file is dual licensed under the terms of the Apache License, Version |
| # 2.0, and the BSD License. See the LICENSE file in the root of this repository |
| # for complete details. |
| |
| import operator |
| import os |
| import platform |
| import sys |
| from typing import Any, Callable, Dict, List, Optional, Tuple, Union |
| |
| from ._parser import ( |
| MarkerAtom, |
| MarkerList, |
| Op, |
| Value, |
| Variable, |
| parse_marker as _parse_marker, |
| ) |
| from ._tokenizer import ParserSyntaxError |
| from .specifiers import InvalidSpecifier, Specifier |
| from .utils import canonicalize_name |
| |
| __all__ = [ |
| "InvalidMarker", |
| "UndefinedComparison", |
| "UndefinedEnvironmentName", |
| "Marker", |
| "default_environment", |
| ] |
| |
| Operator = Callable[[str, str], bool] |
| |
| |
| class InvalidMarker(ValueError): |
| """ |
| An invalid marker was found, users should refer to PEP 508. |
| """ |
| |
| |
| class UndefinedComparison(ValueError): |
| """ |
| An invalid operation was attempted on a value that doesn't support it. |
| """ |
| |
| |
| class UndefinedEnvironmentName(ValueError): |
| """ |
| A name was attempted to be used that does not exist inside of the |
| environment. |
| """ |
| |
| |
| def _normalize_extra_values(results: Any) -> Any: |
| """ |
| Normalize extra values. |
| """ |
| if isinstance(results[0], tuple): |
| lhs, op, rhs = results[0] |
| if isinstance(lhs, Variable) and lhs.value == "extra": |
| normalized_extra = canonicalize_name(rhs.value) |
| rhs = Value(normalized_extra) |
| elif isinstance(rhs, Variable) and rhs.value == "extra": |
| normalized_extra = canonicalize_name(lhs.value) |
| lhs = Value(normalized_extra) |
| results[0] = lhs, op, rhs |
| return results |
| |
| |
| def _format_marker( |
| marker: Union[List[str], MarkerAtom, str], first: Optional[bool] = True |
| ) -> str: |
| |
| assert isinstance(marker, (list, tuple, str)) |
| |
| # Sometimes we have a structure like [[...]] which is a single item list |
| # where the single item is itself it's own list. In that case we want skip |
| # the rest of this function so that we don't get extraneous () on the |
| # outside. |
| if ( |
| isinstance(marker, list) |
| and len(marker) == 1 |
| and isinstance(marker[0], (list, tuple)) |
| ): |
| return _format_marker(marker[0]) |
| |
| if isinstance(marker, list): |
| inner = (_format_marker(m, first=False) for m in marker) |
| if first: |
| return " ".join(inner) |
| else: |
| return "(" + " ".join(inner) + ")" |
| elif isinstance(marker, tuple): |
| return " ".join([m.serialize() for m in marker]) |
| else: |
| return marker |
| |
| |
| _operators: Dict[str, Operator] = { |
| "in": lambda lhs, rhs: lhs in rhs, |
| "not in": lambda lhs, rhs: lhs not in rhs, |
| "<": operator.lt, |
| "<=": operator.le, |
| "==": operator.eq, |
| "!=": operator.ne, |
| ">=": operator.ge, |
| ">": operator.gt, |
| } |
| |
| |
| def _eval_op(lhs: str, op: Op, rhs: str) -> bool: |
| try: |
| spec = Specifier("".join([op.serialize(), rhs])) |
| except InvalidSpecifier: |
| pass |
| else: |
| return spec.contains(lhs, prereleases=True) |
| |
| oper: Optional[Operator] = _operators.get(op.serialize()) |
| if oper is None: |
| raise UndefinedComparison(f"Undefined {op!r} on {lhs!r} and {rhs!r}.") |
| |
| return oper(lhs, rhs) |
| |
| |
| def _normalize(*values: str, key: str) -> Tuple[str, ...]: |
| # PEP 685 – Comparison of extra names for optional distribution dependencies |
| # https://peps.python.org/pep-0685/ |
| # > When comparing extra names, tools MUST normalize the names being |
| # > compared using the semantics outlined in PEP 503 for names |
| if key == "extra": |
| return tuple(canonicalize_name(v) for v in values) |
| |
| # other environment markers don't have such standards |
| return values |
| |
| |
| def _evaluate_markers(markers: MarkerList, environment: Dict[str, str]) -> bool: |
| groups: List[List[bool]] = [[]] |
| |
| for marker in markers: |
| assert isinstance(marker, (list, tuple, str)) |
| |
| if isinstance(marker, list): |
| groups[-1].append(_evaluate_markers(marker, environment)) |
| elif isinstance(marker, tuple): |
| lhs, op, rhs = marker |
| |
| if isinstance(lhs, Variable): |
| environment_key = lhs.value |
| lhs_value = environment[environment_key] |
| rhs_value = rhs.value |
| else: |
| lhs_value = lhs.value |
| environment_key = rhs.value |
| rhs_value = environment[environment_key] |
| |
| lhs_value, rhs_value = _normalize(lhs_value, rhs_value, key=environment_key) |
| groups[-1].append(_eval_op(lhs_value, op, rhs_value)) |
| else: |
| assert marker in ["and", "or"] |
| if marker == "or": |
| groups.append([]) |
| |
| return any(all(item) for item in groups) |
| |
| |
| def format_full_version(info: "sys._version_info") -> str: |
| version = "{0.major}.{0.minor}.{0.micro}".format(info) |
| kind = info.releaselevel |
| if kind != "final": |
| version += kind[0] + str(info.serial) |
| return version |
| |
| |
| def default_environment() -> Dict[str, str]: |
| iver = format_full_version(sys.implementation.version) |
| implementation_name = sys.implementation.name |
| return { |
| "implementation_name": implementation_name, |
| "implementation_version": iver, |
| "os_name": os.name, |
| "platform_machine": platform.machine(), |
| "platform_release": platform.release(), |
| "platform_system": platform.system(), |
| "platform_version": platform.version(), |
| "python_full_version": platform.python_version(), |
| "platform_python_implementation": platform.python_implementation(), |
| "python_version": ".".join(platform.python_version_tuple()[:2]), |
| "sys_platform": sys.platform, |
| } |
| |
| |
| class Marker: |
| def __init__(self, marker: str) -> None: |
| # Note: We create a Marker object without calling this constructor in |
| # packaging.requirements.Requirement. If any additional logic is |
| # added here, make sure to mirror/adapt Requirement. |
| try: |
| self._markers = _normalize_extra_values(_parse_marker(marker)) |
| # The attribute `_markers` can be described in terms of a recursive type: |
| # MarkerList = List[Union[Tuple[Node, ...], str, MarkerList]] |
| # |
| # For example, the following expression: |
| # python_version > "3.6" or (python_version == "3.6" and os_name == "unix") |
| # |
| # is parsed into: |
| # [ |
| # (<Variable('python_version')>, <Op('>')>, <Value('3.6')>), |
| # 'and', |
| # [ |
| # (<Variable('python_version')>, <Op('==')>, <Value('3.6')>), |
| # 'or', |
| # (<Variable('os_name')>, <Op('==')>, <Value('unix')>) |
| # ] |
| # ] |
| except ParserSyntaxError as e: |
| raise InvalidMarker(str(e)) from e |
| |
| def __str__(self) -> str: |
| return _format_marker(self._markers) |
| |
| def __repr__(self) -> str: |
| return f"<Marker('{self}')>" |
| |
| def __hash__(self) -> int: |
| return hash((self.__class__.__name__, str(self))) |
| |
| def __eq__(self, other: Any) -> bool: |
| if not isinstance(other, Marker): |
| return NotImplemented |
| |
| return str(self) == str(other) |
| |
| def evaluate(self, environment: Optional[Dict[str, str]] = None) -> bool: |
| """Evaluate a marker. |
| |
| Return the boolean from evaluating the given marker against the |
| environment. environment is an optional argument to override all or |
| part of the determined environment. |
| |
| The environment is determined from the current Python process. |
| """ |
| current_environment = default_environment() |
| current_environment["extra"] = "" |
| if environment is not None: |
| current_environment.update(environment) |
| # The API used to allow setting extra to None. We need to handle this |
| # case for backwards compatibility. |
| if current_environment["extra"] is None: |
| current_environment["extra"] = "" |
| |
| return _evaluate_markers(self._markers, current_environment) |
