# ******************************************************************************
# getpath.py
# ******************************************************************************
# This script is designed to be precompiled to bytecode, frozen into the
# main binary, and then directly evaluated. It is not an importable module,
# and does not import any other modules (besides winreg on Windows).
# Rather, the values listed below must be specified in the globals dict
# used when evaluating the bytecode.
# See _PyConfig_InitPathConfig in Modules/getpath.c for the execution.
# ******************************************************************************
# REQUIRED GLOBALS
# ******************************************************************************
# ** Helper functions **
# abspath(path) -- make relative paths absolute against CWD
# basename(path) -- the filename of path
# dirname(path) -- the directory name of path
# hassuffix(path, suffix) -- returns True if path has suffix
# isabs(path) -- path is absolute or not
# isdir(path) -- path exists and is a directory
# isfile(path) -- path exists and is a file
# isxfile(path) -- path exists and is an executable file
# joinpath(*paths) -- combine the paths
# readlines(path) -- a list of each line of text in the UTF-8 encoded file
# realpath(path) -- resolves symlinks in path
# warn(message) -- print a warning (if enabled)
# ** Values known at compile time **
# os_name -- [in] one of 'nt', 'posix', 'darwin'
# PREFIX -- [in] sysconfig.get_config_var(...)
# EXEC_PREFIX -- [in] sysconfig.get_config_var(...)
# PYTHONPATH -- [in] sysconfig.get_config_var(...)
# WITH_NEXT_FRAMEWORK -- [in] sysconfig.get_config_var(...)
# VPATH -- [in] sysconfig.get_config_var(...)
# PLATLIBDIR -- [in] sysconfig.get_config_var(...)
# PYDEBUGEXT -- [in, opt] '_d' on Windows for debug builds
# EXE_SUFFIX -- [in, opt] '.exe' on Windows/Cygwin/similar
# VERSION_MAJOR -- [in] sys.version_info.major
# VERSION_MINOR -- [in] sys.version_info.minor
# ABI_THREAD -- [in] either 't' for free-threaded builds or ''
# PYWINVER -- [in] the Windows platform-specific version (e.g. 3.8-32)
# ** Values read from the environment **
# There is no need to check the use_environment flag before reading
# these, as the flag will be tested in this script.
# Also note that ENV_PYTHONPATH is read from config['pythonpath_env']
# to allow for embedders who choose to specify it via that struct.
# ENV_PATH -- [in] getenv(...)
# ENV_PYTHONHOME -- [in] getenv(...)
# ENV_PYTHONEXECUTABLE -- [in] getenv(...)
# ENV___PYVENV_LAUNCHER__ -- [in] getenv(...)
# ** Values calculated at runtime **
# config -- [in/out] dict of the PyConfig structure
# real_executable -- [in, optional] resolved path to main process
# On Windows and macOS, read directly from the running process
# Otherwise, leave None and it will be calculated from executable
# executable_dir -- [in, optional] real directory containing binary
# If None, will be calculated from real_executable or executable
# py_setpath -- [in] argument provided to Py_SetPath
# If None, 'prefix' and 'exec_prefix' may be updated in config
# library -- [in, optional] path of dylib/DLL/so
# Only used for locating ._pth files
# winreg -- [in, optional] the winreg module (only on Windows)
# ******************************************************************************
# HIGH-LEVEL ALGORITHM
# ******************************************************************************
# IMPORTANT: The code is the actual specification at time of writing.
# This prose description is based on the original comment from the old
# getpath.c to help capture the intent, but should not be considered
# a specification.
# Search in some common locations for the associated Python libraries.
# Two directories must be found, the platform independent directory
# (prefix), containing the common .py and .pyc files, and the platform
# dependent directory (exec_prefix), containing the shared library
# modules. Note that prefix and exec_prefix can be the same directory,
# but for some installations, they are different.
# This script carries out separate searches for prefix and exec_prefix.
# Each search tries a number of different locations until a ``landmark''
# file or directory is found. If no prefix or exec_prefix is found, a
# warning message is issued and the preprocessor defined PREFIX and
# EXEC_PREFIX are used (even though they will not work); python carries on
# as best as is possible, but most imports will fail.
# Before any searches are done, the location of the executable is
# determined. If Py_SetPath() was called, or if we are running on
# Windows, the 'real_executable' path is used (if known). Otherwise,
# we use the config-specified program name or default to argv[0].
# If this has one or more slashes in it, it is made absolute against
# the current working directory. If it only contains a name, it must
# have been invoked from the shell's path, so we search $PATH for the
# named executable and use that. If the executable was not found on
# $PATH (or there was no $PATH environment variable), the original
# argv[0] string is used.
# At this point, provided Py_SetPath was not used, the
# __PYVENV_LAUNCHER__ variable may override the executable (on macOS,
# the PYTHON_EXECUTABLE variable may also override). This allows
# certain launchers that run Python as a subprocess to properly
# specify the executable path. They are not intended for users.
# Next, the executable location is examined to see if it is a symbolic
# link. If so, the link is realpath-ed and the directory of the link
# target is used for the remaining searches. The same steps are
# performed for prefix and for exec_prefix, but with different landmarks.
# Step 1. Are we running in a virtual environment? Unless 'home' has
# been specified another way, check for a pyvenv.cfg and use its 'home'
# property to override the executable dir used later for prefix searches.
# We do not activate the venv here - that is performed later by site.py.
# Step 2. Is there a ._pth file? A ._pth file lives adjacent to the
# runtime library (if any) or the actual executable (not the symlink),
# and contains precisely the intended contents of sys.path as relative
# paths (to its own location). Its presence also enables isolated mode
# and suppresses other environment variable usage. Unless already
# specified by Py_SetHome(), the directory containing the ._pth file is
# set as 'home'.
# Step 3. Are we running python out of the build directory? This is
# checked by looking for the BUILDDIR_TXT file, which contains the
# relative path to the platlib dir. The executable_dir value is
# derived from joining the VPATH preprocessor variable to the
# directory containing pybuilddir.txt. If it is not found, the
# BUILD_LANDMARK file is found, which is part of the source tree.
# prefix is then found by searching up for a file that should only
# exist in the source tree, and the stdlib dir is set to prefix/Lib.
# Step 4. If 'home' is set, either by Py_SetHome(), ENV_PYTHONHOME,
# a pyvenv.cfg file, ._pth file, or by detecting a build directory, it
# is assumed to point to prefix and exec_prefix. $PYTHONHOME can be a
# single directory, which is used for both, or the prefix and exec_prefix
# directories separated by DELIM (colon on POSIX; semicolon on Windows).
# Step 5. Try to find prefix and exec_prefix relative to executable_dir,
# backtracking up the path until it is exhausted. This is the most common
# step to succeed. Note that if prefix and exec_prefix are different,
# exec_prefix is more likely to be found; however if exec_prefix is a
# subdirectory of prefix, both will be found.
# Step 6. Search the directories pointed to by the preprocessor variables
# PREFIX and EXEC_PREFIX. These are supplied by the Makefile but can be
# passed in as options to the configure script.
# That's it!
# Well, almost. Once we have determined prefix and exec_prefix, the
# preprocessor variable PYTHONPATH is used to construct a path. Each
# relative path on PYTHONPATH is prefixed with prefix. Then the directory
# containing the shared library modules is appended. The environment
# variable $PYTHONPATH is inserted in front of it all. On POSIX, if we are
# in a build directory, both prefix and exec_prefix are reset to the
# corresponding preprocessor variables (so sys.prefix will reflect the
# installation location, even though sys.path points into the build
# directory). This seems to make more sense given that currently the only
# known use of sys.prefix and sys.exec_prefix is for the ILU installation
# process to find the installed Python tree.
# An embedding application can use Py_SetPath() to override all of
# these automatic path computations.
# ******************************************************************************
# PLATFORM CONSTANTS
# ******************************************************************************
platlibdir = config.get('platlibdir') or PLATLIBDIR
ABI_THREAD = ABI_THREAD or ''
if os_name == 'posix' or os_name == 'darwin':
BUILDDIR_TXT = 'pybuilddir.txt'
BUILD_LANDMARK = 'Modules/Setup.local'
DEFAULT_PROGRAM_NAME = f'python{VERSION_MAJOR}'
STDLIB_SUBDIR = f'{platlibdir}/python{VERSION_MAJOR}.{VERSION_MINOR}{ABI_THREAD}'
STDLIB_LANDMARKS = [f'{STDLIB_SUBDIR}/os.py', f'{STDLIB_SUBDIR}/os.pyc']
PLATSTDLIB_LANDMARK = f'{platlibdir}/python{VERSION_MAJOR}.{VERSION_MINOR}{ABI_THREAD}/lib-dynload'
BUILDSTDLIB_LANDMARKS = ['Lib/os.py']
VENV_LANDMARK = 'pyvenv.cfg'
ZIP_LANDMARK = f'{platlibdir}/python{VERSION_MAJOR}{VERSION_MINOR}{ABI_THREAD}.zip'
DELIM = ':'
SEP = '/'
elif os_name == 'nt':
BUILDDIR_TXT = 'pybuilddir.txt'
BUILD_LANDMARK = f'{VPATH}\\Modules\\Setup.local'
DEFAULT_PROGRAM_NAME = f'python'
STDLIB_SUBDIR = 'Lib'
STDLIB_LANDMARKS = [f'{STDLIB_SUBDIR}\\os.py', f'{STDLIB_SUBDIR}\\os.pyc']
PLATSTDLIB_LANDMARK = f'{platlibdir}'
BUILDSTDLIB_LANDMARKS = ['Lib\\os.py']
VENV_LANDMARK = 'pyvenv.cfg'
ZIP_LANDMARK = f'python{VERSION_MAJOR}{VERSION_MINOR}{PYDEBUGEXT or ""}.zip'
WINREG_KEY = f'SOFTWARE\\Python\\PythonCore\\{PYWINVER}\\PythonPath'
DELIM = ';'
SEP = '\\'
# ******************************************************************************
# HELPER FUNCTIONS (note that we prefer C functions for performance)
# ******************************************************************************
def search_up(prefix, *landmarks, test=isfile):
while prefix:
if any(test(joinpath(prefix, f)) for f in landmarks):
return prefix
prefix = dirname(prefix)
# ******************************************************************************
# READ VARIABLES FROM config
# ******************************************************************************
program_name = config.get('program_name')
home = config.get('home')
executable = config.get('executable')
base_executable = config.get('base_executable')
prefix = config.get('prefix')
exec_prefix = config.get('exec_prefix')
base_prefix = config.get('base_prefix')
base_exec_prefix = config.get('base_exec_prefix')
ENV_PYTHONPATH = config['pythonpath_env']
use_environment = config.get('use_environment', 1)
pythonpath = config.get('module_search_paths')
pythonpath_was_set = config.get('module_search_paths_set')
stdlib_dir = config.get('stdlib_dir')
stdlib_dir_was_set_in_config = bool(stdlib_dir)
real_executable_dir = None
platstdlib_dir = None
# ******************************************************************************
# CALCULATE program_name
# ******************************************************************************
if not program_name:
try:
program_name = config.get('orig_argv', [])[0]
except IndexError:
pass
if not program_name:
program_name = DEFAULT_PROGRAM_NAME
if EXE_SUFFIX and not hassuffix(program_name, EXE_SUFFIX) and isxfile(program_name + EXE_SUFFIX):
program_name = program_name + EXE_SUFFIX
# ******************************************************************************
# CALCULATE executable
# ******************************************************************************
if py_setpath:
# When Py_SetPath has been called, executable defaults to
# the real executable path.
if not executable:
executable = real_executable
if not executable and SEP in program_name:
# Resolve partial path program_name against current directory
executable = abspath(program_name)
if not executable:
# All platforms default to real_executable if known at this
# stage. POSIX does not set this value.
executable = real_executable
elif os_name == 'darwin':
# QUIRK: On macOS we may know the real executable path, but
# if our caller has lied to us about it (e.g. most of
# test_embed), we need to use their path in order to detect
# whether we are in a build tree. This is true even if the
# executable path was provided in the config.
real_executable = executable
if not executable and program_name and ENV_PATH:
# Resolve names against PATH.
# NOTE: The use_environment value is ignored for this lookup.
# To properly isolate, launch Python with a full path.
for p in ENV_PATH.split(DELIM):
p = joinpath(p, program_name)
if isxfile(p):
executable = p
break
if not executable:
executable = ''
# When we cannot calculate the executable, subsequent searches
# look in the current working directory. Here, we emulate that
# (the former getpath.c would do it apparently by accident).
executable_dir = abspath('.')
# Also need to set this fallback in case we are running from a
# build directory with an invalid argv0 (i.e. test_sys.test_executable)
real_executable_dir = executable_dir
if ENV_PYTHONEXECUTABLE or ENV___PYVENV_LAUNCHER__:
# If set, these variables imply that we should be using them as
# sys.executable and when searching for venvs. However, we should
# use the argv0 path for prefix calculation
if os_name == 'darwin' and WITH_NEXT_FRAMEWORK:
# In a framework build the binary in {sys.exec_prefix}/bin is
# a stub executable that execs the real interpreter in an
# embedded app bundle. That bundle is an implementation detail
# and should not affect base_executable.
base_executable = f"{dirname(library)}/bin/python{VERSION_MAJOR}.{VERSION_MINOR}"
else:
# Use the real executable as our base, or argv[0] otherwise
# (on Windows, argv[0] is likely to be ENV___PYVENV_LAUNCHER__; on
# other platforms, real_executable is likely to be empty)
base_executable = real_executable or executable
if not real_executable:
real_executable = base_executable
#real_executable_dir = dirname(real_executable)
executable = ENV_PYTHONEXECUTABLE or ENV___PYVENV_LAUNCHER__
executable_dir = dirname(executable)
# ******************************************************************************
# CALCULATE (default) home
# ******************************************************************************
# Used later to distinguish between Py_SetPythonHome and other
# ways that it may have been set
home_was_set = False
if home:
home_was_set = True
elif use_environment and ENV_PYTHONHOME and not py_setpath:
home = ENV_PYTHONHOME
# ******************************************************************************
# READ pyvenv.cfg
# ******************************************************************************
venv_prefix = None
# Calling Py_SetPythonHome(), Py_SetPath() or
# setting $PYTHONHOME will override venv detection.
if not home and not py_setpath:
try:
# prefix2 is just to avoid calculating dirname again later,
# as the path in venv_prefix is the more common case.
venv_prefix2 = executable_dir or dirname(executable)
venv_prefix = dirname(venv_prefix2)
try:
# Read pyvenv.cfg from one level above executable
pyvenvcfg = readlines(joinpath(venv_prefix, VENV_LANDMARK))
except (FileNotFoundError, PermissionError):
# Try the same directory as executable
pyvenvcfg = readlines(joinpath(venv_prefix2, VENV_LANDMARK))
venv_prefix = venv_prefix2
except (FileNotFoundError, PermissionError):
venv_prefix = None
pyvenvcfg = []
for line in pyvenvcfg:
key, had_equ, value = line.partition('=')
if had_equ and key.strip().lower() == 'home':
executable_dir = real_executable_dir = value.strip()
if not base_executable:
# First try to resolve symlinked executables, since that may be
# more accurate than assuming the executable in 'home'.
try:
base_executable = realpath(executable)
if base_executable == executable:
# No change, so probably not a link. Clear it and fall back
base_executable = ''
except OSError:
pass
if not base_executable:
base_executable = joinpath(executable_dir, basename(executable))
# It's possible "python" is executed from within a posix venv but that
# "python" is not available in the "home" directory as the standard
# `make install` does not create it and distros often do not provide it.
#
# In this case, try to fall back to known alternatives
if os_name != 'nt' and not isfile(base_executable):
base_exe = basename(executable)
for candidate in (DEFAULT_PROGRAM_NAME, f'python{VERSION_MAJOR}.{VERSION_MINOR}'):
candidate += EXE_SUFFIX if EXE_SUFFIX else ''
if base_exe == candidate:
continue
candidate = joinpath(executable_dir, candidate)
# Only set base_executable if the candidate exists.
# If no candidate succeeds, subsequent errors related to
# base_executable (like FileNotFoundError) remain in the
# context of the original executable name
if isfile(candidate):
base_executable = candidate
break
break
else:
venv_prefix = None
# ******************************************************************************
# CALCULATE base_executable, real_executable AND executable_dir
# ******************************************************************************
if not base_executable:
base_executable = executable or real_executable or ''
if not real_executable:
real_executable = base_executable
if real_executable:
try:
real_executable = realpath(real_executable)
except OSError as ex:
# Only warn if the file actually exists and was unresolvable
# Otherwise users who specify a fake executable may get spurious warnings.
if isfile(real_executable):
warn(f'Failed to find real location of {real_executable}')
if not executable_dir and os_name == 'darwin' and library:
# QUIRK: macOS checks adjacent to its library early
library_dir = dirname(library)
if any(isfile(joinpath(library_dir, p)) for p in STDLIB_LANDMARKS):
# Exceptions here should abort the whole process (to match
# previous behavior)
executable_dir = realpath(library_dir)
real_executable_dir = executable_dir
# If we do not have the executable's directory, we can calculate it.
# This is the directory used to find prefix/exec_prefix if necessary.
if not executable_dir and real_executable:
executable_dir = real_executable_dir = dirname(real_executable)
# If we do not have the real executable's directory, we calculate it.
# This is the directory used to detect build layouts.
if not real_executable_dir and real_executable:
real_executable_dir = dirname(real_executable)
# ******************************************************************************
# DETECT _pth FILE
# ******************************************************************************
# The contents of an optional ._pth file are used to totally override
# sys.path calculation. Its presence also implies isolated mode and
# no-site (unless explicitly requested)
pth = None
pth_dir = None
# Calling Py_SetPythonHome() or Py_SetPath() will override ._pth search,
# but environment variables and command-line options cannot.
if not py_setpath and not home_was_set:
# 1. Check adjacent to the main DLL/dylib/so (if set)
# 2. Check adjacent to the original executable
# 3. Check adjacent to our actual executable
# This may allow a venv to override the base_executable's
# ._pth file, but it cannot override the library's one.
for p in [library, executable, real_executable]:
if p:
if os_name == 'nt' and (hassuffix(p, 'exe') or hassuffix(p, 'dll')):
p = p.rpartition('.')[0]
p += '._pth'
try:
pth = readlines(p)
pth_dir = dirname(p)
break
except OSError:
pass
# If we found a ._pth file, disable environment and home
# detection now. Later, we will do the rest.
if pth_dir:
use_environment = 0
home = pth_dir
pythonpath = []
# ******************************************************************************
# CHECK FOR BUILD DIRECTORY
# ******************************************************************************
build_prefix = None
if ((not home_was_set and real_executable_dir and not py_setpath)
or config.get('_is_python_build', 0) > 0):
# Detect a build marker and use it to infer prefix, exec_prefix,
# stdlib_dir and the platstdlib_dir directories.
try:
platstdlib_dir = joinpath(
real_executable_dir,
readlines(joinpath(real_executable_dir, BUILDDIR_TXT))[0],
)
build_prefix = joinpath(real_executable_dir, VPATH)
except IndexError:
# File exists but is empty
platstdlib_dir = real_executable_dir
build_prefix = joinpath(real_executable_dir, VPATH)
except (FileNotFoundError, PermissionError):
if isfile(joinpath(real_executable_dir, BUILD_LANDMARK)):
build_prefix = joinpath(real_executable_dir, VPATH)
if os_name == 'nt':
# QUIRK: Windows builds need platstdlib_dir to be the executable
# dir. Normally the builddir marker handles this, but in this
# case we need to correct manually.
platstdlib_dir = real_executable_dir
if build_prefix:
if os_name == 'nt':
# QUIRK: No searching for more landmarks on Windows
build_stdlib_prefix = build_prefix
else:
build_stdlib_prefix = search_up(build_prefix, *BUILDSTDLIB_LANDMARKS)
# Use the build prefix for stdlib when not explicitly set
if not stdlib_dir_was_set_in_config:
if build_stdlib_prefix:
stdlib_dir = joinpath(build_stdlib_prefix, 'Lib')
else:
stdlib_dir = joinpath(build_prefix, 'Lib')
# Only use the build prefix for prefix if it hasn't already been set
if not prefix:
prefix = build_stdlib_prefix
# Do not warn, because 'prefix' never equals 'build_prefix' on POSIX
#elif not venv_prefix and prefix != build_prefix:
# warn('Detected development environment but prefix is already set')
if not exec_prefix:
exec_prefix = build_prefix
# Do not warn, because 'exec_prefix' never equals 'build_prefix' on POSIX
#elif not venv_prefix and exec_prefix != build_prefix:
# warn('Detected development environment but exec_prefix is already set')
config['_is_python_build'] = 1
# ******************************************************************************
# CALCULATE prefix AND exec_prefix
# ******************************************************************************
if py_setpath:
# As documented, calling Py_SetPath will force both prefix
# and exec_prefix to the empty string.
prefix = exec_prefix = ''
else:
# Read prefix and exec_prefix from explicitly set home
if home:
# When multiple paths are listed with ':' or ';' delimiters,
# split into prefix:exec_prefix
prefix, had_delim, exec_prefix = home.partition(DELIM)
if not had_delim:
exec_prefix = prefix
# Reset the standard library directory if it was not explicitly set
if not stdlib_dir_was_set_in_config:
stdlib_dir = None
# First try to detect prefix by looking alongside our runtime library, if known
if library and not prefix:
library_dir = dirname(library)
if ZIP_LANDMARK:
if os_name == 'nt':
# QUIRK: Windows does not search up for ZIP file
if isfile(joinpath(library_dir, ZIP_LANDMARK)):
prefix = library_dir
else:
prefix = search_up(library_dir, ZIP_LANDMARK)
if STDLIB_SUBDIR and STDLIB_LANDMARKS and not prefix:
if any(isfile(joinpath(library_dir, f)) for f in STDLIB_LANDMARKS):
prefix = library_dir
if not stdlib_dir_was_set_in_config:
stdlib_dir = joinpath(prefix, STDLIB_SUBDIR)
# Detect prefix by looking for zip file
if ZIP_LANDMARK and executable_dir and not prefix:
if os_name == 'nt':
# QUIRK: Windows does not search up for ZIP file
if isfile(joinpath(executable_dir, ZIP_LANDMARK)):
prefix = executable_dir
else:
prefix = search_up(executable_dir, ZIP_LANDMARK)
if prefix and not stdlib_dir_was_set_in_config:
stdlib_dir = joinpath(prefix, STDLIB_SUBDIR)
if not isdir(stdlib_dir):
stdlib_dir = None
# Detect prefix by searching from our executable location for the stdlib_dir
if STDLIB_SUBDIR and STDLIB_LANDMARKS and executable_dir and not prefix:
prefix = search_up(executable_dir, *STDLIB_LANDMARKS)
if prefix and not stdlib_dir:
stdlib_dir = joinpath(prefix, STDLIB_SUBDIR)
if PREFIX and not prefix:
prefix = PREFIX
if not any(isfile(joinpath(prefix, f)) for f in STDLIB_LANDMARKS):
warn('Could not find platform independent libraries <prefix>')
if not prefix:
prefix = abspath('')
warn('Could not find platform independent libraries <prefix>')
# Detect exec_prefix by searching from executable for the platstdlib_dir
if PLATSTDLIB_LANDMARK and not exec_prefix:
if os_name == 'nt':
# QUIRK: Windows always assumed these were the same
# gh-100320: Our PYDs are assumed to be relative to the Lib directory
# (that is, prefix) rather than the executable (that is, executable_dir)
exec_prefix = prefix
if not exec_prefix and executable_dir:
exec_prefix = search_up(executable_dir, PLATSTDLIB_LANDMARK, test=isdir)
if not exec_prefix and EXEC_PREFIX:
exec_prefix = EXEC_PREFIX
if not exec_prefix or not isdir(joinpath(exec_prefix, PLATSTDLIB_LANDMARK)):
if os_name == 'nt':
# QUIRK: If DLLs is missing on Windows, don't warn, just assume
# that they're in exec_prefix
if not platstdlib_dir:
# gh-98790: We set platstdlib_dir here to avoid adding "DLLs" into
# sys.path when it doesn't exist in the platstdlib place, which
# would give Lib packages precedence over executable_dir where our
# PYDs *probably* live. Ideally, whoever changes our layout will tell
# us what the layout is, but in the past this worked, so it should
# keep working.
platstdlib_dir = exec_prefix
else:
warn('Could not find platform dependent libraries <exec_prefix>')
# Fallback: assume exec_prefix == prefix
if not exec_prefix:
exec_prefix = prefix
if not prefix or not exec_prefix:
warn('Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>]')
# For a venv, update the main prefix/exec_prefix but leave the base ones unchanged
if venv_prefix:
if not base_prefix:
base_prefix = prefix
if not base_exec_prefix:
base_exec_prefix = exec_prefix
prefix = exec_prefix = venv_prefix
# After calculating prefix and exec_prefix, use their values for base_prefix and
# base_exec_prefix if they haven't been set.
if not base_prefix:
base_prefix = prefix
if not base_exec_prefix:
base_exec_prefix = exec_prefix
# ******************************************************************************
# UPDATE pythonpath (sys.path)
# ******************************************************************************
if py_setpath:
# If Py_SetPath was called then it overrides any existing search path
config['module_search_paths'] = py_setpath.split(DELIM)
config['module_search_paths_set'] = 1
elif not pythonpath_was_set:
# If pythonpath was already explicitly set or calculated, we leave it alone.
# This won't matter in normal use, but if an embedded host is trying to
# recalculate paths while running then we do not want to change it.
pythonpath = []
# First add entries from the process environment
if use_environment and ENV_PYTHONPATH:
for p in ENV_PYTHONPATH.split(DELIM):
pythonpath.append(abspath(p))
# Then add the default zip file
if os_name == 'nt':
# QUIRK: Windows uses the library directory rather than the prefix
if library:
library_dir = dirname(library)
else:
library_dir = executable_dir
pythonpath.append(joinpath(library_dir, ZIP_LANDMARK))
elif build_prefix:
# QUIRK: POSIX uses the default prefix when in the build directory
pythonpath.append(joinpath(PREFIX, ZIP_LANDMARK))
else:
pythonpath.append(joinpath(base_prefix, ZIP_LANDMARK))
if os_name == 'nt' and use_environment and winreg:
# QUIRK: Windows also lists paths in the registry. Paths are stored
# as the default value of each subkey of
# {HKCU,HKLM}\Software\Python\PythonCore\{winver}\PythonPath
# where winver is sys.winver (typically '3.x' or '3.x-32')
for hk in (winreg.HKEY_CURRENT_USER, winreg.HKEY_LOCAL_MACHINE):
try:
key = winreg.OpenKeyEx(hk, WINREG_KEY)
try:
i = 0
while True:
try:
v = winreg.QueryValue(key, winreg.EnumKey(key, i))
except OSError:
break
if isinstance(v, str):
pythonpath.extend(v.split(DELIM))
i += 1
# Paths from the core key get appended last, but only
# when home was not set and we haven't found our stdlib
# some other way.
if not home and not stdlib_dir:
v = winreg.QueryValue(key, None)
if isinstance(v, str):
pythonpath.extend(v.split(DELIM))
finally:
winreg.CloseKey(key)
except OSError:
pass
# Then add any entries compiled into the PYTHONPATH macro.
if PYTHONPATH:
for p in PYTHONPATH.split(DELIM):
pythonpath.append(joinpath(base_prefix, p))
# Then add stdlib_dir and platstdlib_dir
if not stdlib_dir and base_prefix:
stdlib_dir = joinpath(base_prefix, STDLIB_SUBDIR)
if not platstdlib_dir and base_exec_prefix:
platstdlib_dir = joinpath(base_exec_prefix, PLATSTDLIB_LANDMARK)
if os_name == 'nt':
# QUIRK: Windows generates paths differently
if platstdlib_dir:
pythonpath.append(platstdlib_dir)
if stdlib_dir:
pythonpath.append(stdlib_dir)
if executable_dir and executable_dir not in pythonpath:
# QUIRK: the executable directory is on sys.path
# We keep it low priority, so that properly installed modules are
# found first. It may be earlier in the order if we found some
# reason to put it there.
pythonpath.append(executable_dir)
else:
if stdlib_dir:
pythonpath.append(stdlib_dir)
if platstdlib_dir:
pythonpath.append(platstdlib_dir)
config['module_search_paths'] = pythonpath
config['module_search_paths_set'] = 1
# ******************************************************************************
# POSIX prefix/exec_prefix QUIRKS
# ******************************************************************************
# QUIRK: Non-Windows replaces prefix/exec_prefix with defaults when running
# in build directory. This happens after pythonpath calculation.
# Virtual environments using the build directory Python still keep their prefix.
if os_name != 'nt' and build_prefix:
if not venv_prefix:
prefix = config.get('prefix') or PREFIX
exec_prefix = config.get('exec_prefix') or EXEC_PREFIX or prefix
base_prefix = config.get('base_prefix') or PREFIX
base_exec_prefix = config.get('base_exec_prefix') or EXEC_PREFIX or base_prefix
# ******************************************************************************
# SET pythonpath FROM _PTH FILE
# ******************************************************************************
if pth:
config['isolated'] = 1
config['use_environment'] = 0
config['site_import'] = 0
config['safe_path'] = 1
pythonpath = []
for line in pth:
line = line.partition('#')[0].strip()
if not line:
pass
elif line == 'import site':
config['site_import'] = 1
elif line.startswith('import '):
warn("unsupported 'import' line in ._pth file")
else:
pythonpath.append(joinpath(pth_dir, line))
config['module_search_paths'] = pythonpath
config['module_search_paths_set'] = 1
# ******************************************************************************
# UPDATE config FROM CALCULATED VALUES
# ******************************************************************************
config['program_name'] = program_name
config['home'] = home
config['executable'] = executable
config['base_executable'] = base_executable
config['prefix'] = prefix
config['exec_prefix'] = exec_prefix
config['base_prefix'] = base_prefix
config['base_exec_prefix'] = base_exec_prefix
config['platlibdir'] = platlibdir
# test_embed expects empty strings, not None
config['stdlib_dir'] = stdlib_dir or ''
config['platstdlib_dir'] = platstdlib_dir or ''
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