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# -*- coding: utf-8 -*-
"""
A simple shim module to fix up things on Python 2 only.
Note: until we setup correctly the paths we can only import built-ins.
"""
import sys
def main():
"""Patch what needed, and invoke the original site.py"""
here = __file__ # the distutils.install patterns will be injected relative to this site.py, save it here
config = read_pyvenv()
sys.real_prefix = sys.base_prefix = config["base-prefix"]
sys.base_exec_prefix = config["base-exec-prefix"]
sys.base_executable = config["base-executable"]
global_site_package_enabled = config.get("include-system-site-packages", False) == "true"
rewrite_standard_library_sys_path()
disable_user_site_package()
load_host_site(here)
if global_site_package_enabled:
add_global_site_package()
rewrite_getsitepackages(here)
def load_host_site(here):
"""trigger reload of site.py - now it will use the standard library instance that will take care of init"""
# we have a duality here, we generate the platform and pure library path based on what distutils.install specifies
# because this is what pip will be using; the host site.py though may contain it's own pattern for where the
# platform and pure library paths should exist
# notably on Ubuntu there's a patch for getsitepackages to point to
# - prefix + local/lib/pythonx.y/dist-packages
# - prefix + lib/pythonx.y/dist-packages
# while distutils.install.cmd still points both of these to
# - prefix + lib/python2.7/site-packages
# to facilitate when the two match, or not we first reload the site.py, now triggering the import of host site.py,
# as this will ensure that initialization code within host site.py runs
# ___RELOAD_CODE___
# and then if the distutils site packages are not on the sys.path we add them via add_site_dir; note we must add
# them by invoking add_site_dir to trigger the processing of pth files
add_site_dir = sys.modules["site"].addsitedir
for path in get_site_packages_dirs(here):
add_site_dir(path)
def get_site_packages_dirs(here):
import json
import os
site_packages = r"""
___EXPECTED_SITE_PACKAGES___
"""
for path in json.loads(site_packages):
yield os.path.abspath(os.path.join(here, path.encode("utf-8")))
sep = "\\" if sys.platform == "win32" else "/" # no os module here yet - poor mans version
def read_pyvenv():
"""read pyvenv.cfg"""
config_file = "{}{}pyvenv.cfg".format(sys.prefix, sep)
with open(config_file) as file_handler:
lines = file_handler.readlines()
config = {}
for line in lines:
try:
split_at = line.index("=")
except ValueError:
continue # ignore bad/empty lines
else:
config[line[:split_at].strip()] = line[split_at + 1 :].strip()
return config
def rewrite_standard_library_sys_path():
"""Once this site file is loaded the standard library paths have already been set, fix them up"""
exe, prefix, exec_prefix = get_exe_prefixes(base=False)
base_exe, base_prefix, base_exec = get_exe_prefixes(base=True)
exe_dir = exe[: exe.rfind(sep)]
for at, path in enumerate(sys.path):
path = abs_path(path) # replace old sys prefix path starts with new
skip_rewrite = path == exe_dir # don't fix the current executable location, notably on Windows this gets added
skip_rewrite = skip_rewrite # ___SKIP_REWRITE____
if not skip_rewrite:
sys.path[at] = map_path(path, base_exe, exe_dir, exec_prefix, base_prefix, prefix, base_exec)
# the rewrite above may have changed elements from PYTHONPATH, revert these if on
if sys.flags.ignore_environment:
return
import os
python_paths = []
if "PYTHONPATH" in os.environ and os.environ["PYTHONPATH"]:
for path in os.environ["PYTHONPATH"].split(os.pathsep):
if path not in python_paths:
python_paths.append(path)
sys.path[: len(python_paths)] = python_paths
def get_exe_prefixes(base=False):
return tuple(abs_path(getattr(sys, ("base_" if base else "") + i)) for i in ("executable", "prefix", "exec_prefix"))
def abs_path(value):
values, keep = value.split(sep), []
at = len(values) - 1
while at >= 0:
if values[at] == "..":
at -= 1
else:
keep.append(values[at])
at -= 1
return sep.join(keep[::-1])
def map_path(path, base_executable, exe_dir, exec_prefix, base_prefix, prefix, base_exec_prefix):
if path_starts_with(path, exe_dir):
# content inside the exe folder needs to remap to original executables folder
orig_exe_folder = base_executable[: base_executable.rfind(sep)]
return "{}{}".format(orig_exe_folder, path[len(exe_dir) :])
elif path_starts_with(path, prefix):
return "{}{}".format(base_prefix, path[len(prefix) :])
elif path_starts_with(path, exec_prefix):
return "{}{}".format(base_exec_prefix, path[len(exec_prefix) :])
return path
def path_starts_with(directory, value):
return directory.startswith(value if value[-1] == sep else value + sep)
def disable_user_site_package():
"""Flip the switch on enable user site package"""
# sys.flags is a c-extension type, so we cannot monkeypatch it, replace it with a python class to flip it
sys.original_flags = sys.flags
class Flags(object):
def __init__(self):
self.__dict__ = {key: getattr(sys.flags, key) for key in dir(sys.flags) if not key.startswith("_")}
sys.flags = Flags()
sys.flags.no_user_site = 1
def add_global_site_package():
"""add the global site package"""
import site
# add user site package
sys.flags = sys.original_flags # restore original
site.ENABLE_USER_SITE = None # reset user site check
# add the global site package to the path - use new prefix and delegate to site.py
orig_prefixes = None
try:
orig_prefixes = site.PREFIXES
site.PREFIXES = [sys.base_prefix, sys.base_exec_prefix]
site.main()
finally:
site.PREFIXES = orig_prefixes + site.PREFIXES
# Debian and it's derivatives patch this function. We undo the damage
def rewrite_getsitepackages(here):
site = sys.modules["site"]
site_package_dirs = get_site_packages_dirs(here)
orig_getsitepackages = site.getsitepackages
def getsitepackages():
sitepackages = orig_getsitepackages()
if sys.prefix not in site.PREFIXES or sys.exec_prefix not in site.PREFIXES:
# Someone messed with the prefixes, so we stop patching
return sitepackages
for path in site_package_dirs:
if path not in sitepackages:
sitepackages.insert(0, path)
return sitepackages
site.getsitepackages = getsitepackages
main()
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