all Python 3Modules & importsfunction

runpy.run_module()

running

Locates a module by name through the import system and executes its code, returning its globals dictionary — this is how python -m works.

Syntax

runpy.run_module(mod_name, init_globals=None, run_name=None, alter_sys=False)

By default __name__ is the module name, so the if __name__ == '__main__' block does not run — pass run_name='__main__' to mimic python -m. The module is executed afresh on every call and is not left in sys.modules. Without alter_sys=True, sys.argv[0] and sys.modules['__main__'] are unchanged, and the executed code sees the caller's arguments.

Examples

import runpy, sys
sys.path.insert(0, '.')
with open('tool.py', 'w') as f:
    f.write('x = 6 * 7\nif __name__ == "__main__":\n    print("main!")\n')
g = runpy.run_module('tool')
print(g['x'], g['__name__'])  # → 42 tool
g = runpy.run_module('tool', run_name='__main__')  # → main!
print('tool' in sys.modules)  # → False

See also

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