Why do people write #!/usr/bin/env python on the first line of a Python script?

Question

It seems to me like the files run the same without that line.

Answer 1

You can try this issue using virtualenv

Here is test.py

#! /usr/bin/env python
import sys
print(sys.version)

Create virtual environments

virtualenv test2.6 -p /usr/bin/python2.6
virtualenv test2.7 -p /usr/bin/python2.7

activate each environment then check the differences

echo $PATH
./test.py