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# 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 pip._vendor.pyparsing import ParseException, ParseResults, stringStart, stringEnd
from pip._vendor.pyparsing import ZeroOrMore, Group, Forward, QuotedString
from pip._vendor.pyparsing import Literal as L # noqa
from ._compat import string_types
from ._typing import TYPE_CHECKING
from .specifiers import Specifier, InvalidSpecifier
if TYPE_CHECKING: # pragma: no cover
from typing import Any, Callable, Dict, List, Optional, Tuple, Union
Operator = Callable[[str, str], bool]
__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):
# type: (Any) -> None
self.value = value
def __str__(self):
# type: () -> str
return str(self.value)
def __repr__(self):
# type: () -> str
return "<{0}({1!r})>".format(self.__class__.__name__, str(self))
def serialize(self):
# type: () -> str
raise NotImplementedError
class Variable(Node):
def serialize(self):
# type: () -> str
return str(self)
class Value(Node):
def serialize(self):
# type: () -> str
return '"{0}"'.format(self)
class Op(Node):
def serialize(self):
# type: () -> str
return str(self)
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") # PEP-508
)
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_OP.setParseAction(lambda s, l, t: Op(t[0]))
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):
# type: (Union[ParseResults, List[Any]]) -> List[Any]
if isinstance(results, ParseResults):
return [_coerce_parse_result(i) for i in results]
else:
return results
def _format_marker(marker, first=True):
# type: (Union[List[str], Tuple[Node, ...], str], Optional[bool]) -> str
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 " ".join([m.serialize() for m in 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,
} # type: Dict[str, Operator]
def _eval_op(lhs, op, rhs):
# type: (str, Op, str) -> bool
try:
spec = Specifier("".join([op.serialize(), rhs]))
except InvalidSpecifier:
pass
else:
return spec.contains(lhs)
oper = _operators.get(op.serialize()) # type: Optional[Operator]
if oper is None:
raise UndefinedComparison(
"Undefined {0!r} on {1!r} and {2!r}.".format(op, lhs, rhs)
)
return oper(lhs, rhs)
class Undefined(object):
pass
_undefined = Undefined()
def _get_env(environment, name):
# type: (Dict[str, str], str) -> str
value = environment.get(name, _undefined) # type: Union[str, Undefined]
if isinstance(value, Undefined):
raise UndefinedEnvironmentName(
"{0!r} does not exist in evaluation environment.".format(name)
)
return value
def _evaluate_markers(markers, environment):
# type: (List[Any], Dict[str, str]) -> bool
groups = [[]] # type: List[List[bool]]
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):
# type: (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():
# type: () -> Dict[str, str]
if hasattr(sys, "implementation"):
# Ignoring the `sys.implementation` reference for type checking due to
# mypy not liking that the attribute doesn't exist in Python 2.7 when
# run with the `--py27` flag.
iver = format_full_version(sys.implementation.version) # type: ignore
implementation_name = sys.implementation.name # type: ignore
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": ".".join(platform.python_version_tuple()[:2]),
"sys_platform": sys.platform,
}
class Marker(object):
def __init__(self, marker):
# type: (str) -> None
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):
# type: () -> str
return _format_marker(self._markers)
def __repr__(self):
# type: () -> str
return "<Marker({0!r})>".format(str(self))
def evaluate(self, environment=None):
# type: (Optional[Dict[str, str]]) -> 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()
if environment is not None:
current_environment.update(environment)
return _evaluate_markers(self._markers, current_environment)
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