cpython/Lib/zipapp.py

180 lines
6.3 KiB
Python

import contextlib
import os
import pathlib
import shutil
import stat
import sys
import zipfile
__all__ = ['ZipAppError', 'create_archive', 'get_interpreter']
# The __main__.py used if the users specifies "-m module:fn".
# Note that this will always be written as UTF-8 (module and
# function names can be non-ASCII in Python 3).
# We add a coding cookie even though UTF-8 is the default in Python 3
# because the resulting archive may be intended to be run under Python 2.
MAIN_TEMPLATE = """\
# -*- coding: utf-8 -*-
import {module}
{module}.{fn}()
"""
# The Windows launcher defaults to UTF-8 when parsing shebang lines if the
# file has no BOM. So use UTF-8 on Windows.
# On Unix, use the filesystem encoding.
if sys.platform.startswith('win'):
shebang_encoding = 'utf-8'
else:
shebang_encoding = sys.getfilesystemencoding()
class ZipAppError(ValueError):
pass
@contextlib.contextmanager
def _maybe_open(archive, mode):
if isinstance(archive, str):
with open(archive, mode) as f:
yield f
else:
yield archive
def _write_file_prefix(f, interpreter):
"""Write a shebang line."""
if interpreter:
shebang = b'#!%b\n' % (interpreter.encode(shebang_encoding),)
f.write(shebang)
def _copy_archive(archive, new_archive, interpreter=None):
"""Copy an application archive, modifying the shebang line."""
with _maybe_open(archive, 'rb') as src:
# Skip the shebang line from the source.
# Read 2 bytes of the source and check if they are #!.
first_2 = src.read(2)
if first_2 == b'#!':
# Discard the initial 2 bytes and the rest of the shebang line.
first_2 = b''
src.readline()
with _maybe_open(new_archive, 'wb') as dst:
_write_file_prefix(dst, interpreter)
# If there was no shebang, "first_2" contains the first 2 bytes
# of the source file, so write them before copying the rest
# of the file.
dst.write(first_2)
shutil.copyfileobj(src, dst)
if interpreter and isinstance(new_archive, str):
os.chmod(new_archive, os.stat(new_archive).st_mode | stat.S_IEXEC)
def create_archive(source, target=None, interpreter=None, main=None):
"""Create an application archive from SOURCE.
The SOURCE can be the name of a directory, or a filename or a file-like
object referring to an existing archive.
The content of SOURCE is packed into an application archive in TARGET,
which can be a filename or a file-like object. If SOURCE is a directory,
TARGET can be omitted and will default to the name of SOURCE with .pyz
appended.
The created application archive will have a shebang line specifying
that it should run with INTERPRETER (there will be no shebang line if
INTERPRETER is None), and a __main__.py which runs MAIN (if MAIN is
not specified, an existing __main__.py will be used). It is an to specify
MAIN for anything other than a directory source with no __main__.py, and it
is an error to omit MAIN if the directory has no __main__.py.
"""
# Are we copying an existing archive?
if not (isinstance(source, str) and os.path.isdir(source)):
_copy_archive(source, target, interpreter)
return
# We are creating a new archive from a directory.
has_main = os.path.exists(os.path.join(source, '__main__.py'))
if main and has_main:
raise ZipAppError(
"Cannot specify entry point if the source has __main__.py")
if not (main or has_main):
raise ZipAppError("Archive has no entry point")
main_py = None
if main:
# Check that main has the right format.
mod, sep, fn = main.partition(':')
mod_ok = all(part.isidentifier() for part in mod.split('.'))
fn_ok = all(part.isidentifier() for part in fn.split('.'))
if not (sep == ':' and mod_ok and fn_ok):
raise ZipAppError("Invalid entry point: " + main)
main_py = MAIN_TEMPLATE.format(module=mod, fn=fn)
if target is None:
target = source + '.pyz'
with _maybe_open(target, 'wb') as fd:
_write_file_prefix(fd, interpreter)
with zipfile.ZipFile(fd, 'w') as z:
root = pathlib.Path(source)
for child in root.rglob('*'):
arcname = str(child.relative_to(root))
z.write(str(child), arcname)
if main_py:
z.writestr('__main__.py', main_py.encode('utf-8'))
if interpreter and isinstance(target, str):
os.chmod(target, os.stat(target).st_mode | stat.S_IEXEC)
def get_interpreter(archive):
with _maybe_open(archive, 'rb') as f:
if f.read(2) == b'#!':
return f.readline().strip().decode(shebang_encoding)
def main():
import argparse
parser = argparse.ArgumentParser()
parser.add_argument('--output', '-o', default=None,
help="The name of the output archive. "
"Required if SOURCE is an archive.")
parser.add_argument('--python', '-p', default=None,
help="The name of the Python interpreter to use "
"(default: no shebang line).")
parser.add_argument('--main', '-m', default=None,
help="The main function of the application "
"(default: use an existing __main__.py).")
parser.add_argument('--info', default=False, action='store_true',
help="Display the interpreter from the archive.")
parser.add_argument('source',
help="Source directory (or existing archive).")
args = parser.parse_args()
# Handle `python -m zipapp archive.pyz --info`.
if args.info:
if not os.path.isfile(args.source):
raise SystemExit("Can only get info for an archive file")
interpreter = get_interpreter(args.source)
print("Interpreter: {}".format(interpreter or "<none>"))
sys.exit(0)
if os.path.isfile(args.source):
if args.output is None or os.path.samefile(args.source, args.output):
raise SystemExit("In-place editing of archives is not supported")
if args.main:
raise SystemExit("Cannot change the main function when copying")
create_archive(args.source, args.output,
interpreter=args.python, main=args.main)
if __name__ == '__main__':
main()