Pass Variable to Python in Bash Script

Question

I'm trying to transfer a variable in a bash-script to an embedded python-function. A minimal example of the script I'm using is given below:

#!/bin/bash
function python_print() {
PYTHON_ARG="1ドル" python - <<END
import os
p = str(os.environ['PYTHON_ARG'])
print('The Variable is ' + p)
END
}
DIRIN=1ドル
FULLPATH=$ realpath $OUTFILE
python_print $FULLPATH

Running the script gives me: "The variable is "; so it seems the argument FULLPATH is not transfered to the function. The strange thing is, the code works if "$FULLPATH" is replaced either with "1ドル", "$DIRIN" or any hardcoded string. Where is my mistake? I'm grateful for any advice!

• Bailey Parker: But where is OUTFILE ever defined?
• SpoonMeiser: If instead of python_print $FULLPATH you did echo $FULLPATH does it print the value you expect? I suspect the line above is meant to be FULLPATH=$(realpath $OUTFILE)
• Stephan H: @Bailey Parker: My mistake, I tried to post a minimal example of my original script, so I accidently deleted the line "OUTFILE=2ドル".

Answer 1

The problem is not in python_print function (note that function keyword is redundant with ()). but in FULLPATH assignment and function call

correct syntax

FULLPATH=$(realpath "$OUTFILE")
python_print "$FULLPATH"

• no space between = and value in assignment
• double quotes around variable expansion in function call
• expansion must be double quoted except
  • if $ appears just after = in assignment
  • conditions between double brackets [[ ]]

note that

FULLPATH=$ realpath $OUTFILE

is not affecting FULLPATH in current shell process environment, it just sets FULLPATH to $ to realpath execution process environment also output is not captured.

Answer 2

Just either:

• export your bash variable so it is available in os.environ
• or use positional parameters and read it from sys.argv