Difference between :pyf % and :!python % for running python code

Question

I use to map F9 to :pyf % to run python files from vim . But after reading this answer , which suggests

nnoremap <buffer> <F9> :exec '!python' shellescape(@%, 1)<cr>

Just wondering which approach should be preferred for running python code from vim session.

Answer 1

:pyfile is a variant of :python (that reads the code from a file, not as direct arguments). Both execute the code inside Vim's embedded Python interpreter . This is mostly meant for Vim plugins written in Python. You have access to Vim's Python interface (cp. :help python-vim ), and any code / globals will persist until you quit Vim.

For trivial code without side effects, this should be fine, although it's not meant for that.

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:!python ... launches an external Python interpreter , completely separate from Vim. Vim doesn't even need to be compiled with Python support here. As each invocation is a separate process, there's no persistence between runs. Each one is fresh, just like launching the script directly from the command-line. Also, you're using the system's default Python interpreter, not the one Vim was compiled against.

I would recommend this approach, unless you're explicitly writing a Vim plugin.

Answer 2

:pythonfile executes the file with Python built-in into vim so the script can import module vim .

!python executes external interpreter that doesn't have any access to vim internals.