Is It Possible To Check If Python Sourcecode Was Written Only For One Version (python 2 Or Python 3)

I make some source code analysis and need to know if the source code was written only for one version (python 2 or python 3). Ideally without starting the script with both runtimes

Solution 1:

You cannot reliably detect that code was written for Python 3 only.

If code uses print as a statement you can be certain it will only work on Python 2. Similarly, code using except Exception, target: is only going to run on Python 2.

But it is possible to write polyglot Python code; code that'll run on both Python 2 and 3, by using from __future__ statements; from __future__ import print_function will let you use the print() function on Python 2, for example.

Your best bet is to go through the major Python 3 syntax changes, and create a series of heuristics to make an educated guess about the Python version.

The Python-Future project has a helpful cheatsheet that probably is of help here too.