CODEWITHSUNDEEP
pythonpython-3.x
Chris Jefferson
Chris Jefferson

Reputation: 7157

Execute current Python script in Python 3

I have a python program which I have made work in both Python 2 and 3, and it has more functionality in Python 3 (using new Python 3 features).

My script currently starts #!/usr/bin/env python, as that seems to be the mostly likely name for a python executable. However, what I'd like to do is "if python3 exists, use that, if not use python".

I would prefer not to have to distribute multiple files / and extra script (at present my program is a single distributed python file).

Is there an easy way to run the current script in python3, if it exists?

Upvotes: 0

Views: 86

Answers (3)

user8408080
user8408080

Reputation: 2468

Maybe I didn't quite get what you want. I understood: You want to look if there is Python 3 installed on the Computer and if so, use it. Inside the script you can check the version with sys.version as Idlehands mentioned. To get the latest version you might want to use a small bash script like this

py_versions=($(ls /usr/bin | grep 'python[0-9]\.[0-9]$'))
${py_versions[-1]} your_script.py

This searches the output of ls for all python versions and stores them in py_versions. Thankfully the output is already sorted, so the last element in the array will be the latest version.

Upvotes: 0

r.ook
r.ook

Reputation: 13868

Another better method modified from this question is to check the sys.version:

import sys
py_ver = sys.version[0]

Original answer: May not be the best method, but one way to do it is test against a function that only exist in one version of Python to know what you are running off of.

try:
    raw_input
    py_ver = 2

except NameError:
    py_ver = 3

if py_ver==2:
   ... Python 2 stuff

elif py_ver==3:
   ... Python 3 stuff

Upvotes: 1

Krilosax
Krilosax

Reputation: 13

Try with version_info from sys package

Upvotes: 0

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