93 lines
3.1 KiB
Python
Executable File
93 lines
3.1 KiB
Python
Executable File
"""runpy.py - locating and running Python code using the module namespace
|
|
|
|
Provides support for locating and running Python scripts using the Python
|
|
module namespace instead of the native filesystem.
|
|
|
|
This allows Python code to play nicely with non-filesystem based PEP 302
|
|
importers when locating support scripts as well as when importing modules.
|
|
"""
|
|
# Written by Nick Coghlan <ncoghlan at gmail.com>
|
|
# to implement PEP 338 (Executing Modules as Scripts)
|
|
|
|
import sys
|
|
import imp
|
|
try:
|
|
from imp import get_loader
|
|
except ImportError:
|
|
from pkgutil import get_loader
|
|
|
|
__all__ = [
|
|
"run_module",
|
|
]
|
|
|
|
|
|
def _run_code(code, run_globals, init_globals,
|
|
mod_name, mod_fname, mod_loader):
|
|
"""Helper for _run_module_code"""
|
|
if init_globals is not None:
|
|
run_globals.update(init_globals)
|
|
run_globals.update(__name__ = mod_name,
|
|
__file__ = mod_fname,
|
|
__loader__ = mod_loader)
|
|
exec(code, run_globals)
|
|
return run_globals
|
|
|
|
def _run_module_code(code, init_globals=None,
|
|
mod_name=None, mod_fname=None,
|
|
mod_loader=None, alter_sys=False):
|
|
"""Helper for run_module"""
|
|
# Set up the top level namespace dictionary
|
|
if alter_sys:
|
|
# Modify sys.argv[0] and sys.modules[mod_name]
|
|
sys.argv[0] = mod_fname
|
|
module = imp.new_module(mod_name)
|
|
sys.modules[mod_name] = module
|
|
mod_globals = module.__dict__
|
|
else:
|
|
# Leave the sys module alone
|
|
mod_globals = {}
|
|
return _run_code(code, mod_globals, init_globals,
|
|
mod_name, mod_fname, mod_loader)
|
|
|
|
|
|
# This helper is needed due to a missing component in the PEP 302
|
|
# loader protocol (specifically, "get_filename" is non-standard)
|
|
def _get_filename(loader, mod_name):
|
|
try:
|
|
get_filename = loader.get_filename
|
|
except AttributeError:
|
|
return None
|
|
else:
|
|
return get_filename(mod_name)
|
|
|
|
|
|
def run_module(mod_name, init_globals=None,
|
|
run_name=None, alter_sys=False):
|
|
"""Execute a module's code without importing it
|
|
|
|
Returns the resulting top level namespace dictionary
|
|
"""
|
|
loader = get_loader(mod_name)
|
|
if loader is None:
|
|
raise ImportError("No module named %s" % mod_name)
|
|
if loader.is_package(mod_name):
|
|
raise ImportError(("%s is a package and cannot " +
|
|
"be directly executed") % mod_name)
|
|
code = loader.get_code(mod_name)
|
|
if code is None:
|
|
raise ImportError("No code object available for %s" % mod_name)
|
|
filename = _get_filename(loader, mod_name)
|
|
if run_name is None:
|
|
run_name = mod_name
|
|
return _run_module_code(code, init_globals, run_name,
|
|
filename, loader, alter_sys)
|
|
|
|
|
|
if __name__ == "__main__":
|
|
# Run the module specified as the next command line argument
|
|
if len(sys.argv) < 2:
|
|
print("No module specified for execution", file=sys.stderr)
|
|
else:
|
|
del sys.argv[0] # Make the requested module sys.argv[0]
|
|
run_module(sys.argv[0], run_name="__main__", alter_sys=True)
|