CODEWITHSUNDEEP
pythonimportmodulecompiled
Jonno
Jonno

Reputation: 787

Is it possible to import a compiled python file?

I can't seem to figure out how to import a compiled .pyc module into my code so I can use it within my main script. Is this even possible?

Upvotes: 26

Views: 50482

Answers (6)

Karoly Horvath
Karoly Horvath

Reputation: 96286

import module

If there's a .py source file, the core will automatically use the .pyc if it's up to date.

If there's no source, python will automatically import .pyc.

Read more about “compiled” Python files here.

Upvotes: 2

Nagev
Nagev

Reputation: 13285

In a nutshell, to import a Python compiled file (e.g. module.pyc) only, simply place it in the same directory where the source (e.g module.py) would be, and ensure that there is no corresponding source file (module.py in our example) there. Then the usual import module will work seamlessly.

If there is a source file in the same directory as the compiled file, Python will use the compiled file in the __pycache__ directory instead, or recompile from source if it's not there.

If you remove the source file without putting a ".pyc" in the same directory, the import will fail even if the compiled file exists in the __pycache__ directory. Also note that files under __pycache__ follow a different naming convention. If you copy them across, make sure that they are renamed so that it has the same name as the source file, except that the extension must be "pyc" rather than "py".

There is a very nice flow chart in PEP 3147 linked from the documentation.

Upvotes: 17

fantadisco
fantadisco

Reputation: 21

Yes, but caveat that with make sure to start python with the "-O" option! In my personal experience, if all you have is that .pyc or .pyo file, running "python.exe" without the flag and trying to import will fail, however running python.exe -O and then trying to import as normal should work.

Upvotes: 1

evotopid
evotopid

Reputation: 5429

Use the import without the extension. Python will than look if the file has changed, if not it will use the previously created pyc file.

But note that if you really want more performance, I recommend you to use PyPy which is a lot faster than the standard CPython implementation. (But note that it is still Python 2)

Upvotes: 3

Intra
Intra

Reputation: 2109

If there is foo.pyc, import foo will automatically use foo.pyc whether foo.py exists or not

(If foo.py is newer, it will be used)

http://docs.python.org/tutorial/modules.html

Upvotes: 24

Kratos85
Kratos85

Reputation: 193

In import use the pyc file name,python will automatically load it.

Upvotes: 0

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