Nick Coghlan | e2ebb2d | 2006-03-15 11:00:26 +0000 | [diff] [blame] | 1 | """runpy.py - locating and running Python code using the module namespace |
| 2 | |
| 3 | Provides support for locating and running Python scripts using the Python |
| 4 | module namespace instead of the native filesystem. |
| 5 | |
| 6 | This allows Python code to play nicely with non-filesystem based PEP 302 |
| 7 | importers when locating support scripts as well as when importing modules. |
| 8 | """ |
| 9 | # Written by Nick Coghlan <ncoghlan at gmail.com> |
| 10 | # to implement PEP 338 (Executing Modules as Scripts) |
| 11 | |
| 12 | import sys |
| 13 | import imp |
Phillip J. Eby | ab1d245 | 2006-04-17 20:17:25 +0000 | [diff] [blame] | 14 | try: |
| 15 | from imp import get_loader |
| 16 | except ImportError: |
| 17 | from pkgutil import get_loader |
Nick Coghlan | e2ebb2d | 2006-03-15 11:00:26 +0000 | [diff] [blame] | 18 | |
| 19 | __all__ = [ |
| 20 | "run_module", |
| 21 | ] |
| 22 | |
Nick Coghlan | e2ebb2d | 2006-03-15 11:00:26 +0000 | [diff] [blame] | 23 | |
Nick Coghlan | 999a336 | 2006-06-28 10:41:47 +0000 | [diff] [blame] | 24 | def _run_code(code, run_globals, init_globals, run_name, |
Nick Coghlan | e2ebb2d | 2006-03-15 11:00:26 +0000 | [diff] [blame] | 25 | mod_name, mod_fname, mod_loader): |
| 26 | """Helper for _run_module_code""" |
| 27 | if init_globals is not None: |
| 28 | run_globals.update(init_globals) |
Nick Coghlan | 999a336 | 2006-06-28 10:41:47 +0000 | [diff] [blame] | 29 | run_globals.update(__name__ = run_name, |
| 30 | __module_name__ = mod_name, |
Nick Coghlan | e2ebb2d | 2006-03-15 11:00:26 +0000 | [diff] [blame] | 31 | __file__ = mod_fname, |
| 32 | __loader__ = mod_loader) |
| 33 | exec code in run_globals |
| 34 | return run_globals |
| 35 | |
Nick Coghlan | 999a336 | 2006-06-28 10:41:47 +0000 | [diff] [blame] | 36 | def _run_module_code(code, init_globals=None, run_name=None, |
Nick Coghlan | e2ebb2d | 2006-03-15 11:00:26 +0000 | [diff] [blame] | 37 | mod_name=None, mod_fname=None, |
| 38 | mod_loader=None, alter_sys=False): |
| 39 | """Helper for run_module""" |
| 40 | # Set up the top level namespace dictionary |
| 41 | if alter_sys: |
| 42 | # Modify sys.argv[0] and sys.module[mod_name] |
| 43 | temp_module = imp.new_module(mod_name) |
| 44 | mod_globals = temp_module.__dict__ |
| 45 | saved_argv0 = sys.argv[0] |
Nick Coghlan | 999a336 | 2006-06-28 10:41:47 +0000 | [diff] [blame] | 46 | sentinel = object() |
| 47 | module_mod_name = sys.modules.get(mod_name, sentinel) |
| 48 | module_run_name = sys.modules.get(run_name, sentinel) |
Nick Coghlan | c841bb6 | 2006-03-24 13:05:53 +0000 | [diff] [blame] | 49 | sys.argv[0] = mod_fname |
| 50 | sys.modules[mod_name] = temp_module |
Nick Coghlan | 999a336 | 2006-06-28 10:41:47 +0000 | [diff] [blame] | 51 | if run_name != mod_name: |
| 52 | sys.modules[run_name] = temp_module |
Nick Coghlan | e2ebb2d | 2006-03-15 11:00:26 +0000 | [diff] [blame] | 53 | try: |
Nick Coghlan | 999a336 | 2006-06-28 10:41:47 +0000 | [diff] [blame] | 54 | _run_code(code, mod_globals, init_globals, run_name, |
Nick Coghlan | c841bb6 | 2006-03-24 13:05:53 +0000 | [diff] [blame] | 55 | mod_name, mod_fname, mod_loader) |
Nick Coghlan | e2ebb2d | 2006-03-15 11:00:26 +0000 | [diff] [blame] | 56 | finally: |
Nick Coghlan | c841bb6 | 2006-03-24 13:05:53 +0000 | [diff] [blame] | 57 | sys.argv[0] = saved_argv0 |
Nick Coghlan | 999a336 | 2006-06-28 10:41:47 +0000 | [diff] [blame] | 58 | if module_mod_name is not sentinel: |
| 59 | sys.modules[mod_name] = module_mod_name |
| 60 | else: |
| 61 | del sys.modules[mod_name] |
| 62 | if run_name != mod_name: |
| 63 | if module_run_name is not sentinel: |
| 64 | sys.modules[run_name] = module_run_name |
| 65 | else: |
| 66 | del sys.modules[run_name] |
Nick Coghlan | e2ebb2d | 2006-03-15 11:00:26 +0000 | [diff] [blame] | 67 | # Copy the globals of the temporary module, as they |
| 68 | # may be cleared when the temporary module goes away |
| 69 | return mod_globals.copy() |
| 70 | else: |
| 71 | # Leave the sys module alone |
Nick Coghlan | 999a336 | 2006-06-28 10:41:47 +0000 | [diff] [blame] | 72 | return _run_code(code, {}, init_globals, run_name, |
Nick Coghlan | e2ebb2d | 2006-03-15 11:00:26 +0000 | [diff] [blame] | 73 | mod_name, mod_fname, mod_loader) |
| 74 | |
| 75 | |
Phillip J. Eby | ab1d245 | 2006-04-17 20:17:25 +0000 | [diff] [blame] | 76 | # This helper is needed due to a missing component in the PEP 302 |
| 77 | # loader protocol (specifically, "get_filename" is non-standard) |
| 78 | def _get_filename(loader, mod_name): |
| 79 | try: |
| 80 | get_filename = loader.get_filename |
| 81 | except AttributeError: |
| 82 | return None |
| 83 | else: |
| 84 | return get_filename(mod_name) |
| 85 | |
| 86 | |
Nick Coghlan | e2ebb2d | 2006-03-15 11:00:26 +0000 | [diff] [blame] | 87 | def run_module(mod_name, init_globals=None, |
| 88 | run_name=None, alter_sys=False): |
| 89 | """Execute a module's code without importing it |
Tim Peters | f99b816 | 2006-03-15 18:08:37 +0000 | [diff] [blame] | 90 | |
Nick Coghlan | e2ebb2d | 2006-03-15 11:00:26 +0000 | [diff] [blame] | 91 | Returns the resulting top level namespace dictionary |
| 92 | """ |
Phillip J. Eby | ab1d245 | 2006-04-17 20:17:25 +0000 | [diff] [blame] | 93 | loader = get_loader(mod_name) |
Nick Coghlan | e2ebb2d | 2006-03-15 11:00:26 +0000 | [diff] [blame] | 94 | if loader is None: |
| 95 | raise ImportError("No module named " + mod_name) |
| 96 | code = loader.get_code(mod_name) |
| 97 | if code is None: |
| 98 | raise ImportError("No code object available for " + mod_name) |
| 99 | filename = _get_filename(loader, mod_name) |
| 100 | if run_name is None: |
| 101 | run_name = mod_name |
Tim Peters | f99b816 | 2006-03-15 18:08:37 +0000 | [diff] [blame] | 102 | return _run_module_code(code, init_globals, run_name, |
Nick Coghlan | 999a336 | 2006-06-28 10:41:47 +0000 | [diff] [blame] | 103 | mod_name, filename, loader, alter_sys) |
Nick Coghlan | e2ebb2d | 2006-03-15 11:00:26 +0000 | [diff] [blame] | 104 | |
| 105 | |
| 106 | if __name__ == "__main__": |
| 107 | # Run the module specified as the next command line argument |
| 108 | if len(sys.argv) < 2: |
| 109 | print >> sys.stderr, "No module specified for execution" |
| 110 | else: |
| 111 | del sys.argv[0] # Make the requested module sys.argv[0] |
| 112 | run_module(sys.argv[0], run_name="__main__", alter_sys=True) |