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