import textwrap
import os
import subprocess
import sys
import signal
import glob
import itertools
class PathReader:
@staticmethod
def _read_file(filename):
root = os.path.dirname(filename)
return (
os.path.join(root, path.rstrip())
for path in open(filename)
if path.strip()
and not path.startswith('#')
and not path.startswith('import ')
)
@classmethod
def _read(cls, target):
"""
As .pth files aren't honored except in site dirs,
read the paths indicated by them.
"""
pth_files = glob.glob(os.path.join(target, '*.pth'))
file_items = map(cls._read_file, pth_files)
return itertools.chain.from_iterable(file_items)
def _inject_sitecustomize(target):
"""
Create a sitecustomize file in the target that will install
the target as a sitedir.
"""
hook = (
textwrap.dedent(
"""
import site
site.addsitedir({target!r})
"""
)
.lstrip()
.format(**locals())
)
sc_fn = os.path.join(target, 'sitecustomize.py')
with open(sc_fn, 'w') as strm:
strm.write(hook)
def _pythonpath():
return 'JYTHONPATH' if sys.platform.startswith('java') else 'PYTHONPATH'
def _build_env(target):
"""
Prepend target and .pth references in target to PYTHONPATH
"""
key = _pythonpath()
env = dict(os.environ)
suffix = env.get(key)
prefix = (target,)
items = itertools.chain(
prefix, PathReader._read(target), (suffix,) if suffix else ()
)
joined = os.pathsep.join(items)
env[key] = joined
return env
def _setup_env(target):
_inject_sitecustomize(target)
return _build_env(target)
def with_path(target, params):
"""
Launch Python with target on the path and params
"""
def null_handler(signum, frame):
pass
signal.signal(signal.SIGINT, null_handler)
cmd = [sys.executable] + params
return subprocess.Popen(cmd, env=_setup_env(target)).wait()
def with_path_overlay(target, params):
"""
Overlay Python with target on the path and params
"""
cmd = [sys.executable] + params
os.execve(sys.executable, cmd, _setup_env(target))
