shell scripting checking python version

Good question. For me it's working fine. You always should quote evaluated variables ("$X" instead of $X); maybe that fixes your error.

But I propose to use the result of the python script instead of its output:

#!/bin/bashif python -c 'import sys; sys.exit(1 if sys.hexversion<0x03000000 else 0)'then    echo "Fine!"fi

If you like to stay in the shell completely, you also can use the --version option:

case "$(python --version 2>&1)" in    *" 3."*)        echo "Fine!"        ;;    *)        echo "Wrong Python version!"        ;;esac

Maybe that's more readable.

The reason why it doesn't work is because the result stored in $PYTHON_VERSION is not an integer, so your equality test is being done with two different types.

You can change the if to:

if [ $PYTHON_VERSION -eq "0" ]; then     echo "fine!"fi

or you can just do:

if [ $PYTHON_VERSION = 0 ]; then

here is a possible solution

if sys.version_info < (3, 0):    reload(sys)    sys.setdefaultencoding('utf8')else:    raw_input = input

this is from an example I had from sleekxmpp, but it does what you need I believe.