Python Syntax using python -m py_compile

[nordlow]

It would be nice to have a basic Python syntax checker that uses simply

python -m py_compile script.py

to perform syntax check. This would enable basic Python syntax check in just about all vanilla Linux installations without need for installing pylint and flake8 etc.

See https://stackoverflow.com/questions/4284313/how-can-i-check-the-syntax-of-python-script-without-executing-it

[swsnr]

Patch welcome.

[nordlow]

Calling

python -m py_compile /home/per/Work/scripts/fib.py

gives

  File "/home/per/Work/scripts/fib.py", line 9
    iff __name__ == '__main__':
               ^
SyntaxError: invalid syntax

This is the only message format given. Further it stops at first error.

I guess we should set :next-checkers to python-flake8 and python-pylint right?

The column number can be extracted by counting the number-of-spaces-minus-4 from beginning of line to the ^ symbol. According to https://docs.python.org/2/library/py_compile.html there doesn't seem to be any other way. I'm working on a patch.

My current try is

(flycheck-define-checker python-pycompile
  "A Python syntax and style checker using Python's builtin py_compile module."
  :command ("python"
            "-m" "py_compile"
            source)
  :error-patterns
  ((error line-start "  File \"" (file-name) "\", line " line "\n"
          (= 2 (zero-or-more not-newline) "\n")
          "SyntaxError: " (message)))
  :modes python-mode
  :next-checkers (python-flake8
                  python-pylint))

but it doesn't work. What have I missed?

Update: I solved it. Missing space after File.

[swsnr]

Closing in favor of #484