Check Python syntax

A simple way to check if particular script or package will compile (not crash with SyntaxError) on particular version of Python.

It can be used at early stage of Python 3 porting, to enforce usage of new-style print, except, raise and so on, and at the same time retain Python 2.6 compatibility.

Installation

pip install https://github.com/alexanderlukanin13/check-python-syntax/archive/master.zip

All necessary python versions should also be installed.

Usage from code

Import check_python_syntax function and call it upon files and directories.

It returns a simple dictionary {file_path: [is_valid, message]}.

>>> from check_python_syntax import check_python_syntax
>>> check_python_syntax(['/tmp/code'], python_version='3.4')
{u'/tmp/code/x.py': [False, u'  File "/tmp/code/x.py", line 2\n    raise Exception, \'a\'\n                   ^\nSyntaxError: invalid syntax\n'], u'/tmp/code/s.py': [True, u'OK'], u'/tmp/code/z.py': [True, u'OK']}

You can specify multiple targets:

>>> check_python_syntax(['/tmp/code/x.py', '/tmp/code/z.py'], python_version='2.6')
{u'/tmp/code/x.py': [True, u'OK'], u'/tmp/code/z.py': [True, u'OK']}

And multiple versions (first existing version will be used):

>>> check_python_syntax(['/tmp/code/s.py'], python_version=('3.9','3'))
{u'/tmp/code/s.py': [True, u'OK']}
>>> check_python_syntax(['/tmp/code/s.py'], python_version='3.9')
{'<exception>': [False, "No Python executable found for '3.9'"]}

Usage from command line

$ python check_python_syntax.py -v 2.7 -p /tmp/code
{
    "/tmp/code/s.py": [
        true,
        "OK"
    ],
    "/tmp/code/x.py": [
        true,
        "OK"
    ],
    "/tmp/code/z.py": [
        true,
        "OK"
    ]
}
$ echo $?
0
$ python check_python_syntax.py -v 3.4 -p /tmp/code
{
    "/tmp/code/s.py": [
        true,
        "OK"
    ],
    "/tmp/code/x.py": [
        false,
        "  File \"/tmp/code/x.py\", line 2\n    raise Exception, 'a'\n                   ^\nSyntaxError: invalid syntax\n"
    ],
    "/tmp/code/z.py": [
        true,
        "OK"
    ]
}
$ echo $?
1

Tips

Compiled *.pyc files are written to system temp directory (e.g. to /tmp). To achieve better performance, it's highly recommended to use memory file system (tmpfs).

Example /etc/fstab entry:

tmpfs                /tmp                 tmpfs      size=256m             0 0