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"""
The PythonInfo contains information about a concrete instance of a Python interpreter
Note: this file is also used to query target interpreters, so can only use standard library methods
"""
from __future__ import absolute_import, print_function
import json
import logging
import os
import platform
import re
import sys
import sysconfig
import warnings
from collections import OrderedDict, namedtuple
from string import digits
VersionInfo = namedtuple("VersionInfo", ["major", "minor", "micro", "releaselevel", "serial"])
def _get_path_extensions():
return list(OrderedDict.fromkeys([""] + os.environ.get("PATHEXT", "").lower().split(os.pathsep)))
EXTENSIONS = _get_path_extensions()
_CONF_VAR_RE = re.compile(r"\{\w+\}")
class PythonInfo(object):
"""Contains information for a Python interpreter"""
def __init__(self):
def u(v):
return v.decode("utf-8") if isinstance(v, bytes) else v
def abs_path(v):
return None if v is None else os.path.abspath(v) # unroll relative elements from path (e.g. ..)
# qualifies the python
self.platform = u(sys.platform)
self.implementation = u(platform.python_implementation())
if self.implementation == "PyPy":
self.pypy_version_info = tuple(u(i) for i in sys.pypy_version_info)
# this is a tuple in earlier, struct later, unify to our own named tuple
self.version_info = VersionInfo(*[u(i) for i in sys.version_info])
self.architecture = 64 if sys.maxsize > 2**32 else 32
# Used to determine some file names.
# See `CPython3Windows.python_zip()`.
self.version_nodot = sysconfig.get_config_var("py_version_nodot")
self.version = u(sys.version)
self.os = u(os.name)
# information about the prefix - determines python home
self.prefix = u(abs_path(getattr(sys, "prefix", None))) # prefix we think
self.base_prefix = u(abs_path(getattr(sys, "base_prefix", None))) # venv
self.real_prefix = u(abs_path(getattr(sys, "real_prefix", None))) # old virtualenv
# information about the exec prefix - dynamic stdlib modules
self.base_exec_prefix = u(abs_path(getattr(sys, "base_exec_prefix", None)))
self.exec_prefix = u(abs_path(getattr(sys, "exec_prefix", None)))
self.executable = u(abs_path(sys.executable)) # the executable we were invoked via
self.original_executable = u(abs_path(self.executable)) # the executable as known by the interpreter
self.system_executable = self._fast_get_system_executable() # the executable we are based of (if available)
try:
__import__("venv")
has = True
except ImportError:
has = False
self.has_venv = has
self.path = [u(i) for i in sys.path]
self.file_system_encoding = u(sys.getfilesystemencoding())
self.stdout_encoding = u(getattr(sys.stdout, "encoding", None))
scheme_names = sysconfig.get_scheme_names()
if "venv" in scheme_names:
self.sysconfig_scheme = "venv"
self.sysconfig_paths = {
u(i): u(sysconfig.get_path(i, expand=False, scheme=self.sysconfig_scheme))
for i in sysconfig.get_path_names()
}
# we cannot use distutils at all if "venv" exists, distutils don't know it
self.distutils_install = {}
# debian / ubuntu python 3.10 without `python3-distutils` will report
# mangled `local/bin` / etc. names for the default prefix
# intentionally select `posix_prefix` which is the unaltered posix-like paths
elif sys.version_info[:2] == (3, 10) and "deb_system" in scheme_names:
self.sysconfig_scheme = "posix_prefix"
self.sysconfig_paths = {
i: sysconfig.get_path(i, expand=False, scheme=self.sysconfig_scheme) for i in sysconfig.get_path_names()
}
# we cannot use distutils at all if "venv" exists, distutils don't know it
self.distutils_install = {}
else:
self.sysconfig_scheme = None
self.sysconfig_paths = {u(i): u(sysconfig.get_path(i, expand=False)) for i in sysconfig.get_path_names()}
self.distutils_install = {u(k): u(v) for k, v in self._distutils_install().items()}
# https://bugs.python.org/issue22199
makefile = getattr(sysconfig, "get_makefile_filename", getattr(sysconfig, "_get_makefile_filename", None))
self.sysconfig = {
u(k): u(v)
for k, v in [
# a list of content to store from sysconfig
("makefile_filename", makefile()),
]
if k is not None
}
config_var_keys = set()
for element in self.sysconfig_paths.values():
for k in _CONF_VAR_RE.findall(element):
config_var_keys.add(u(k[1:-1]))
config_var_keys.add("PYTHONFRAMEWORK")
self.sysconfig_vars = {u(i): u(sysconfig.get_config_var(i) or "") for i in config_var_keys}
if self.implementation == "PyPy" and sys.version_info.major == 2:
self.sysconfig_vars["implementation_lower"] = "python"
confs = {k: (self.system_prefix if v.startswith(self.prefix) else v) for k, v in self.sysconfig_vars.items()}
self.system_stdlib = self.sysconfig_path("stdlib", confs)
self.system_stdlib_platform = self.sysconfig_path("platstdlib", confs)
self.max_size = getattr(sys, "maxsize", getattr(sys, "maxint", None))
self._creators = None
def _fast_get_system_executable(self):
"""Try to get the system executable by just looking at properties"""
if self.real_prefix or (
self.base_prefix is not None and self.base_prefix != self.prefix
): # if this is a virtual environment
if self.real_prefix is None:
base_executable = getattr(sys, "_base_executable", None) # some platforms may set this to help us
if base_executable is not None: # use the saved system executable if present
if sys.executable != base_executable: # we know we're in a virtual environment, cannot be us
if os.path.exists(base_executable):
return base_executable
# Python may return "python" because it was invoked from the POSIX virtual environment
# however some installs/distributions do not provide a version-less "python" binary in
# the system install location (see PEP 394) so try to fallback to a versioned binary.
#
# Gate this to Python 3.11 as `sys._base_executable` path resolution is now relative to
# the 'home' key from pyvenv.cfg which often points to the system install location.
major, minor = self.version_info.major, self.version_info.minor
if self.os == "posix" and (major, minor) >= (3, 11):
# search relative to the directory of sys._base_executable
base_dir = os.path.dirname(base_executable)
for base_executable in [
os.path.join(base_dir, exe)
for exe in ("python{}".format(major), "python{}.{}".format(major, minor))
]:
if os.path.exists(base_executable):
return base_executable
return None # in this case we just can't tell easily without poking around FS and calling them, bail
# if we're not in a virtual environment, this is already a system python, so return the original executable
# note we must choose the original and not the pure executable as shim scripts might throw us off
return self.original_executable
def install_path(self, key):
result = self.distutils_install.get(key)
if result is None: # use sysconfig if sysconfig_scheme is set or distutils is unavailable
# set prefixes to empty => result is relative from cwd
prefixes = self.prefix, self.exec_prefix, self.base_prefix, self.base_exec_prefix
config_var = {k: "" if v in prefixes else v for k, v in self.sysconfig_vars.items()}
result = self.sysconfig_path(key, config_var=config_var).lstrip(os.sep)
return result
@staticmethod
def _distutils_install():
# use distutils primarily because that's what pip does
# https://github.com/pypa/pip/blob/main/src/pip/_internal/locations.py#L95
# note here we don't import Distribution directly to allow setuptools to patch it
with warnings.catch_warnings(): # disable warning for PEP-632
warnings.simplefilter("ignore")
try:
from distutils import dist
from distutils.command.install import SCHEME_KEYS
except ImportError: # if removed or not installed ignore
return {}
d = dist.Distribution({"script_args": "--no-user-cfg"}) # conf files not parsed so they do not hijack paths
if hasattr(sys, "_framework"):
sys._framework = None # disable macOS static paths for framework
with warnings.catch_warnings(): # disable warning for PEP-632
warnings.simplefilter("ignore")
i = d.get_command_obj("install", create=True)
i.prefix = os.sep # paths generated are relative to prefix that contains the path sep, this makes it relative
i.finalize_options()
result = {key: (getattr(i, "install_{}".format(key))[1:]).lstrip(os.sep) for key in SCHEME_KEYS}
return result
@property
def version_str(self):
return ".".join(str(i) for i in self.version_info[0:3])
@property
def version_release_str(self):
return ".".join(str(i) for i in self.version_info[0:2])
@property
def python_name(self):
version_info = self.version_info
return "python{}.{}".format(version_info.major, version_info.minor)
@property
def is_old_virtualenv(self):
return self.real_prefix is not None
@property
def is_venv(self):
return self.base_prefix is not None and self.version_info.major == 3
def sysconfig_path(self, key, config_var=None, sep=os.sep):
pattern = self.sysconfig_paths[key]
if config_var is None:
config_var = self.sysconfig_vars
else:
base = self.sysconfig_vars.copy()
base.update(config_var)
config_var = base
return pattern.format(**config_var).replace("/", sep)
def creators(self, refresh=False):
if self._creators is None or refresh is True:
from virtualenv.run.plugin.creators import CreatorSelector
self._creators = CreatorSelector.for_interpreter(self)
return self._creators
@property
def system_include(self):
path = self.sysconfig_path(
"include",
{k: (self.system_prefix if v.startswith(self.prefix) else v) for k, v in self.sysconfig_vars.items()},
)
if not os.path.exists(path): # some broken packaging don't respect the sysconfig, fallback to distutils path
# the pattern include the distribution name too at the end, remove that via the parent call
fallback = os.path.join(self.prefix, os.path.dirname(self.install_path("headers")))
if os.path.exists(fallback):
path = fallback
return path
@property
def system_prefix(self):
return self.real_prefix or self.base_prefix or self.prefix
@property
def system_exec_prefix(self):
return self.real_prefix or self.base_exec_prefix or self.exec_prefix
def __unicode__(self):
content = repr(self)
if sys.version_info == 2:
content = content.decode("utf-8")
return content
def __repr__(self):
return "{}({!r})".format(
self.__class__.__name__,
{k: v for k, v in self.__dict__.items() if not k.startswith("_")},
)
def __str__(self):
content = "{}({})".format(
self.__class__.__name__,
", ".join(
"{}={}".format(k, v)
for k, v in (
("spec", self.spec),
(
"system"
if self.system_executable is not None and self.system_executable != self.executable
else None,
self.system_executable,
),
(
"original"
if (
self.original_executable != self.system_executable
and self.original_executable != self.executable
)
else None,
self.original_executable,
),
("exe", self.executable),
("platform", self.platform),
("version", repr(self.version)),
("encoding_fs_io", "{}-{}".format(self.file_system_encoding, self.stdout_encoding)),
)
if k is not None
),
)
return content
@property
def spec(self):
return "{}{}-{}".format(self.implementation, ".".join(str(i) for i in self.version_info), self.architecture)
@classmethod
def clear_cache(cls, app_data):
# this method is not used by itself, so here and called functions can import stuff locally
from virtualenv.discovery.cached_py_info import clear
clear(app_data)
cls._cache_exe_discovery.clear()
def satisfies(self, spec, impl_must_match):
"""check if a given specification can be satisfied by the this python interpreter instance"""
if spec.path:
if self.executable == os.path.abspath(spec.path):
return True # if the path is a our own executable path we're done
if not spec.is_abs:
# if path set, and is not our original executable name, this does not match
basename = os.path.basename(self.original_executable)
spec_path = spec.path
if sys.platform == "win32":
basename, suffix = os.path.splitext(basename)
if spec_path.endswith(suffix):
spec_path = spec_path[: -len(suffix)]
if basename != spec_path:
return False
if impl_must_match:
if spec.implementation is not None and spec.implementation.lower() != self.implementation.lower():
return False
if spec.architecture is not None and spec.architecture != self.architecture:
return False
for our, req in zip(self.version_info[0:3], (spec.major, spec.minor, spec.micro)):
if req is not None and our is not None and our != req:
return False
return True
_current_system = None
_current = None
@classmethod
def current(cls, app_data=None):
"""
This locates the current host interpreter information. This might be different than what we run into in case
the host python has been upgraded from underneath us.
"""
if cls._current is None:
cls._current = cls.from_exe(sys.executable, app_data, raise_on_error=True, resolve_to_host=False)
return cls._current
@classmethod
def current_system(cls, app_data=None):
"""
This locates the current host interpreter information. This might be different than what we run into in case
the host python has been upgraded from underneath us.
"""
if cls._current_system is None:
cls._current_system = cls.from_exe(sys.executable, app_data, raise_on_error=True, resolve_to_host=True)
return cls._current_system
def _to_json(self):
# don't save calculated paths, as these are non primitive types
return json.dumps(self._to_dict(), indent=2)
def _to_dict(self):
data = {var: (getattr(self, var) if var not in ("_creators",) else None) for var in vars(self)}
# noinspection PyProtectedMember
data["version_info"] = data["version_info"]._asdict() # namedtuple to dictionary
return data
@classmethod
def from_exe(cls, exe, app_data=None, raise_on_error=True, ignore_cache=False, resolve_to_host=True, env=None):
"""Given a path to an executable get the python information"""
# this method is not used by itself, so here and called functions can import stuff locally
from virtualenv.discovery.cached_py_info import from_exe
env = os.environ if env is None else env
proposed = from_exe(cls, app_data, exe, env=env, raise_on_error=raise_on_error, ignore_cache=ignore_cache)
# noinspection PyProtectedMember
if isinstance(proposed, PythonInfo) and resolve_to_host:
try:
proposed = proposed._resolve_to_system(app_data, proposed)
except Exception as exception:
if raise_on_error:
raise exception
logging.info("ignore %s due cannot resolve system due to %r", proposed.original_executable, exception)
proposed = None
return proposed
@classmethod
def _from_json(cls, payload):
# the dictionary unroll here is to protect against pypy bug of interpreter crashing
raw = json.loads(payload)
return cls._from_dict(raw.copy())
@classmethod
def _from_dict(cls, data):
data["version_info"] = VersionInfo(**data["version_info"]) # restore this to a named tuple structure
result = cls()
result.__dict__ = data.copy()
return result
@classmethod
def _resolve_to_system(cls, app_data, target):
start_executable = target.executable
prefixes = OrderedDict()
while target.system_executable is None:
prefix = target.real_prefix or target.base_prefix or target.prefix
if prefix in prefixes:
if len(prefixes) == 1:
# if we're linking back to ourselves accept ourselves with a WARNING
logging.info("%r links back to itself via prefixes", target)
target.system_executable = target.executable
break
for at, (p, t) in enumerate(prefixes.items(), start=1):
logging.error("%d: prefix=%s, info=%r", at, p, t)
logging.error("%d: prefix=%s, info=%r", len(prefixes) + 1, prefix, target)
raise RuntimeError("prefixes are causing a circle {}".format("|".join(prefixes.keys())))
prefixes[prefix] = target
target = target.discover_exe(app_data, prefix=prefix, exact=False)
if target.executable != target.system_executable:
target = cls.from_exe(target.system_executable, app_data)
target.executable = start_executable
return target
_cache_exe_discovery = {}
def discover_exe(self, app_data, prefix, exact=True, env=None):
key = prefix, exact
if key in self._cache_exe_discovery and prefix:
logging.debug("discover exe from cache %s - exact %s: %r", prefix, exact, self._cache_exe_discovery[key])
return self._cache_exe_discovery[key]
logging.debug("discover exe for %s in %s", self, prefix)
# we don't know explicitly here, do some guess work - our executable name should tell
possible_names = self._find_possible_exe_names()
possible_folders = self._find_possible_folders(prefix)
discovered = []
env = os.environ if env is None else env
for folder in possible_folders:
for name in possible_names:
info = self._check_exe(app_data, folder, name, exact, discovered, env)
if info is not None:
self._cache_exe_discovery[key] = info
return info
if exact is False and discovered:
info = self._select_most_likely(discovered, self)
folders = os.pathsep.join(possible_folders)
self._cache_exe_discovery[key] = info
logging.debug("no exact match found, chosen most similar of %s within base folders %s", info, folders)
return info
msg = "failed to detect {} in {}".format("|".join(possible_names), os.pathsep.join(possible_folders))
raise RuntimeError(msg)
def _check_exe(self, app_data, folder, name, exact, discovered, env):
exe_path = os.path.join(folder, name)
if not os.path.exists(exe_path):
return None
info = self.from_exe(exe_path, app_data, resolve_to_host=False, raise_on_error=False, env=env)
if info is None: # ignore if for some reason we can't query
return None
for item in ["implementation", "architecture", "version_info"]:
found = getattr(info, item)
searched = getattr(self, item)
if found != searched:
if item == "version_info":
found, searched = ".".join(str(i) for i in found), ".".join(str(i) for i in searched)
executable = info.executable
logging.debug("refused interpreter %s because %s differs %s != %s", executable, item, found, searched)
if exact is False:
discovered.append(info)
break
else:
return info
return None
@staticmethod
def _select_most_likely(discovered, target):
# no exact match found, start relaxing our requirements then to facilitate system package upgrades that
# could cause this (when using copy strategy of the host python)
def sort_by(info):
# we need to setup some priority of traits, this is as follows:
# implementation, major, minor, micro, architecture, tag, serial
matches = [
info.implementation == target.implementation,
info.version_info.major == target.version_info.major,
info.version_info.minor == target.version_info.minor,
info.architecture == target.architecture,
info.version_info.micro == target.version_info.micro,
info.version_info.releaselevel == target.version_info.releaselevel,
info.version_info.serial == target.version_info.serial,
]
priority = sum((1 << pos if match else 0) for pos, match in enumerate(reversed(matches)))
return priority
sorted_discovered = sorted(discovered, key=sort_by, reverse=True) # sort by priority in decreasing order
most_likely = sorted_discovered[0]
return most_likely
def _find_possible_folders(self, inside_folder):
candidate_folder = OrderedDict()
executables = OrderedDict()
executables[os.path.realpath(self.executable)] = None
executables[self.executable] = None
executables[os.path.realpath(self.original_executable)] = None
executables[self.original_executable] = None
for exe in executables.keys():
base = os.path.dirname(exe)
# following path pattern of the current
if base.startswith(self.prefix):
relative = base[len(self.prefix) :]
candidate_folder["{}{}".format(inside_folder, relative)] = None
# or at root level
candidate_folder[inside_folder] = None
return [i for i in candidate_folder.keys() if os.path.exists(i)]
def _find_possible_exe_names(self):
name_candidate = OrderedDict()
for name in self._possible_base():
for at in (3, 2, 1, 0):
version = ".".join(str(i) for i in self.version_info[:at])
for arch in ["-{}".format(self.architecture), ""]:
for ext in EXTENSIONS:
candidate = "{}{}{}{}".format(name, version, arch, ext)
name_candidate[candidate] = None
return list(name_candidate.keys())
def _possible_base(self):
possible_base = OrderedDict()
basename = os.path.splitext(os.path.basename(self.executable))[0].rstrip(digits)
possible_base[basename] = None
possible_base[self.implementation] = None
# python is always the final option as in practice is used by multiple implementation as exe name
if "python" in possible_base:
del possible_base["python"]
possible_base["python"] = None
for base in possible_base:
lower = base.lower()
yield lower
from virtualenv.info import fs_is_case_sensitive
if fs_is_case_sensitive():
if base != lower:
yield base
upper = base.upper()
if upper != base:
yield upper
if __name__ == "__main__":
# dump a JSON representation of the current python
# noinspection PyProtectedMember
argv = sys.argv[1:]
if len(argv) >= 1:
start_cookie = argv[0]
argv = argv[1:]
else:
start_cookie = ""
if len(argv) >= 1:
end_cookie = argv[0]
argv = argv[1:]
else:
end_cookie = ""
sys.argv = sys.argv[:1] + argv
info = PythonInfo()._to_json()
sys.stdout.write("".join((start_cookie[::-1], info, end_cookie[::-1])))
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