Alternative to execfile in Python 3? [duplicate]

Question

This question already has an answer here:

• What is an alternative to execfile in Python 3? 11 answers

Python 2 had the builtin function execfile, which was removed in Python 3.0. This question discusses alternatives for Python 3.0, but some considerable changes have been made since Python 3.0.

What is the best alternative to execfile for Python 3.2, and future Python 3.x versions?

Answer 1

The 2to3 script (also the one in Python 3.2) replaces

execfile(filename, globals, locals)

by

exec(compile(open(filename, "rb").read(), filename, 'exec'), globals, locals)

This seems to be the official recommendation.

Answer 2

execfile(filename)

can be replaced with

exec(open(filename).read())

which works in all versions of Python

Answer 3

In Python3.x this is the closest thing I could come up with to executing a file directly, that matches running python /path/to/somefile.py.

Notes:

• Uses binary reading to avoid encoding issues
• Garenteed to close the file (Python3.x warns about this)
• defines __main__, some scripts depend on this to check if they are loading as a module or not for eg. if __name__ == "__main__"
• setting __file__ is nicer for exception messages and some scripts use __file__ to get the paths of other files relative to them.

def exec_full(filepath):
    import os
    global_namespace = {
        "__file__": filepath,
        "__name__": "__main__",
    }
    with open(filepath, 'rb') as file:
        exec(compile(file.read(), filepath, 'exec'), global_namespace)

# execute the file
exec_full("/path/to/somefile.py")

Answer 4

Standard runpy.run_path is an alternative.