Running python2 script in python3 loaded unix environment

Question

my current bash shell is loaded with python3 but occasionally I tend to run old python2 scripts and I get this error

python/2.7.10/bin/python: error while loading shared libraries: libpython2.7.so.1.0: cannot open shared object file: No such file or directory"

so every-time I had to load python2 back and forth. Is there a way to run python2 script in python3 environment by just changing any environmental variables?

Answer 1

Are you open to virtual envs? Otherwise you can run python2 or python3 from the command line.

As an example, create the following file, hello_world.py :

#!/usr/bin/env python
print "Hello, World!"

Then you can run from the bash shell:

python2 hello_world.py

That should work no problem. However, if you run:

python3 hello_world.py

You will run into the error:

SyntaxError: Missing parentheses in call to 'print'. Did you mean print("Hello, world!")?