Similar command to python’s Try for shellscript?

Question

I need to formulate a . sh to run a code if the first error:

!#/bin/bash

python main.py
python3 main.py

As if it were a python (Try/Except) exception.

I thought about creating two . sh scripts, to use Try in a python file, where it would decide which script runs without errors, but I don’t know if it’s feasible. If so, a good idea, how to have python run these files. sh?

Answer 1

Just use two pipes || (OR)

!#/bin/bash

python main.py || python3 main.py

If the syntax fails in Python 2 (I believe your goal) then it will execute the python3

In the example the script was:

import sys

version = sys.version

# Python 3
# value = f"Version: {version}"

# Python 2 e 3
value = "Version: " + version

print(version)

See that he printed Version 2.7.16

Now if you change the comments of the lines to:

import sys

version = sys.version

# Python 3
value = f"Version: {version}"

# Python 2 e 3
# value = "Version: " + version

print(version)

The result will be Version 3.7.3 (in my case, your machine may have different versions of Python 2 and 3)

You may have noticed that you still have the error when you tried to run a Python2 syntax in Python3, before trying Python3, if you want to "delete" this type of message in the terminal you can use the 2>/dev/null in Python 2:

!#/bin/bash

python main.py 2>/dev/null || python3 main.py

In Python3 do not need, after all if fail in both the error is something else.