| # 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. |
| from __future__ import absolute_import, division, print_function |
| |
| import operator |
| import os |
| import platform |
| import sys |
| |
| from pkg_resources.extern.pyparsing import ParseException, ParseResults, stringStart, stringEnd |
| from pkg_resources.extern.pyparsing import ZeroOrMore, Group, Forward, QuotedString |
| from pkg_resources.extern.pyparsing import Literal as L # noqa |
| |
| from ._compat import string_types |
| from .specifiers import Specifier, InvalidSpecifier |
| |
| |
| __all__ = [ |
| "InvalidMarker", "UndefinedComparison", "UndefinedEnvironmentName", |
| "Marker", "default_environment", |
| ] |
| |
| |
| 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. |
| """ |
| |
| |
| class Node(object): |
| |
| def __init__(self, value): |
| self.value = value |
| |
| def __str__(self): |
| return str(self.value) |
| |
| def __repr__(self): |
| return "<{0}({1!r})>".format(self.__class__.__name__, str(self)) |
| |
| |
| class Variable(Node): |
| pass |
| |
| |
| class Value(Node): |
| pass |
| |
| |
| VARIABLE = ( |
| L("implementation_version") | |
| L("platform_python_implementation") | |
| L("implementation_name") | |
| L("python_full_version") | |
| L("platform_release") | |
| L("platform_version") | |
| L("platform_machine") | |
| L("platform_system") | |
| L("python_version") | |
| L("sys_platform") | |
| L("os_name") | |
| L("os.name") | # PEP-345 |
| L("sys.platform") | # PEP-345 |
| L("platform.version") | # PEP-345 |
| L("platform.machine") | # PEP-345 |
| L("platform.python_implementation") | # PEP-345 |
| L("python_implementation") | # undocumented setuptools legacy |
| L("extra") |
| ) |
| ALIASES = { |
| 'os.name': 'os_name', |
| 'sys.platform': 'sys_platform', |
| 'platform.version': 'platform_version', |
| 'platform.machine': 'platform_machine', |
| 'platform.python_implementation': 'platform_python_implementation', |
| 'python_implementation': 'platform_python_implementation' |
| } |
| VARIABLE.setParseAction(lambda s, l, t: Variable(ALIASES.get(t[0], t[0]))) |
| |
| VERSION_CMP = ( |
| L("===") | |
| L("==") | |
| L(">=") | |
| L("<=") | |
| L("!=") | |
| L("~=") | |
| L(">") | |
| L("<") |
| ) |
| |
| MARKER_OP = VERSION_CMP | L("not in") | L("in") |
| |
| MARKER_VALUE = QuotedString("'") | QuotedString('"') |
| MARKER_VALUE.setParseAction(lambda s, l, t: Value(t[0])) |
| |
| BOOLOP = L("and") | L("or") |
| |
| MARKER_VAR = VARIABLE | MARKER_VALUE |
| |
| MARKER_ITEM = Group(MARKER_VAR + MARKER_OP + MARKER_VAR) |
| MARKER_ITEM.setParseAction(lambda s, l, t: tuple(t[0])) |
| |
| LPAREN = L("(").suppress() |
| RPAREN = L(")").suppress() |
| |
| MARKER_EXPR = Forward() |
| MARKER_ATOM = MARKER_ITEM | Group(LPAREN + MARKER_EXPR + RPAREN) |
| MARKER_EXPR << MARKER_ATOM + ZeroOrMore(BOOLOP + MARKER_EXPR) |
| |
| MARKER = stringStart + MARKER_EXPR + stringEnd |
| |
| |
| def _coerce_parse_result(results): |
| if isinstance(results, ParseResults): |
| return [_coerce_parse_result(i) for i in results] |
| else: |
| return results |
| |
| |
| def _format_marker(marker, first=True): |
| assert isinstance(marker, (list, tuple, string_types)) |
| |
| # 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 '{0} {1} "{2}"'.format(*marker) |
| else: |
| return marker |
| |
| |
| _operators = { |
| "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, op, rhs): |
| try: |
| spec = Specifier("".join([op, rhs])) |
| except InvalidSpecifier: |
| pass |
| else: |
| return spec.contains(lhs) |
| |
| oper = _operators.get(op) |
| if oper is None: |
| raise UndefinedComparison( |
| "Undefined {0!r} on {1!r} and {2!r}.".format(op, lhs, rhs) |
| ) |
| |
| return oper(lhs, rhs) |
| |
| |
| _undefined = object() |
| |
| |
| def _get_env(environment, name): |
| value = environment.get(name, _undefined) |
| |
| if value is _undefined: |
| raise UndefinedEnvironmentName( |
| "{0!r} does not exist in evaluation environment.".format(name) |
| ) |
| |
| return value |
| |
| |
| def _evaluate_markers(markers, environment): |
| groups = [[]] |
| |
| for marker in markers: |
| assert isinstance(marker, (list, tuple, string_types)) |
| |
| if isinstance(marker, list): |
| groups[-1].append(_evaluate_markers(marker, environment)) |
| elif isinstance(marker, tuple): |
| lhs, op, rhs = marker |
| |
| if isinstance(lhs, Variable): |
| lhs_value = _get_env(environment, lhs.value) |
| rhs_value = rhs.value |
| else: |
| lhs_value = lhs.value |
| rhs_value = _get_env(environment, rhs.value) |
| |
| 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): |
| 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(): |
| if hasattr(sys, 'implementation'): |
| iver = format_full_version(sys.implementation.version) |
| implementation_name = sys.implementation.name |
| else: |
| iver = '0' |
| 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": platform.python_version()[:3], |
| "sys_platform": sys.platform, |
| } |
| |
| |
| class Marker(object): |
| |
| def __init__(self, marker): |
| try: |
| self._markers = _coerce_parse_result(MARKER.parseString(marker)) |
| except ParseException as e: |
| err_str = "Invalid marker: {0!r}, parse error at {1!r}".format( |
| marker, marker[e.loc:e.loc + 8]) |
| raise InvalidMarker(err_str) |
| |
| def __str__(self): |
| return _format_marker(self._markers) |
| |
| def __repr__(self): |
| return "<Marker({0!r})>".format(str(self)) |
| |
| def evaluate(self, environment=None): |
| """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() |
| if environment is not None: |
| current_environment.update(environment) |
| |
| return _evaluate_markers(self._markers, current_environment) |
