How to print a python function return value in shell?

Question

def hello():
 return "hello world"

The above is my python code. In the shell I am entering:

fooshell=$(python -c 'import hello; hello.hello()')

but when I do

echo $fooshell

I am getting an empty line.

• abarnert: This is really a shell question. The return value to the shell is a small integer, not a string. Meanwhile, the $(foo) construction doesn't get the return value of foo, it gets what foo printed to standard output. Once you understand that, the Python part is simple: print the string instead of returning it.
• abarnert: (PS, when you exit a Python instance with a non-integer value, I believe it logs the value to stderr and exits with 1. At least that's what sys.exit does. But that doesn't matter in this case, because you're not returning/exiting anything; you're just calling a function, throwing away its result, and falling off the end of the program.)
• ilyas patanam: Thanks, I get it now. Pretty much, the shell can only read from standard output.
• abarnert: Well, no, the shell can also read return values, it's just that reading return values and reading stdout are different things.
• ilyas patanam: so if the shell can read return values, can't I store in a variable and then echo it to stdout? I understand it's inefficient but out of curiosity.

Answer 1

Use print

fooshell=$(python -c 'import hello; print(hello.hello())')

If your hello() method itself doesn't print to stdout.