How to run a python function from Windows 10 command prompt in 'python filename.py funcname' format? - python-3.x

Question

I have the following python file, named hello.py:
print('Hello')
def world():
print('Hello World')
If I type the following within the command prompt for windows 10 I get:
In: python hello.py
Out: 'Hello'
In: python hello.py world
Out: 'Hello'
Notice in the second command prompt, 'Hello World' is not an output. Any reason on why my file can't execute the python function when called in the command line but is able to load the file no problem?
Why do I need this?: I need to submit a larger file that has many functions for a project. For this file to be automatically graded I need to be able to call any given function from it using the specific sequence 'python filename.py functionname.'
Update: Some of the answers below do work, but they do not follow the specific sequence of 'python filename.py functionname' required for my project to be graded. I appreciate the insights that everyone has provided so far.

Answer 1

You can run functions directly from the command prompt by using:
python -c 'from hello import world; world()'
You can run the python interpreter as an alternative. cd to your file directory and launch python:
python
and then import the function from your file:
from hello import world
(Launching the python cmd from the same directory as your file.)
Then, you can run:
>>> world()
Hello World

Answer 2

Try this piece of code and type hello.py only:
print('Hello')
def world():
return'Hello World'
world()
##################################################################
def F1():
print('This is the first function.')
if __name__ == '__main__':
F1()
def F2():
print('This is the second function.')
if __name__ == '__main__':
F2()
now you can use form(file_name) import(function_name) create folder(1) with multiple functions in it and you can try to import the desired function into another folder(2) one at a time not all of them all at once by using this.
pardon me for the mistakes if found any feel free to ask further if this does not elaborate.

Answer 3

I found a solution that works for me:
After digging deeper, I realized that windows passes a sys.argv input that contains a string of all the command prompt inputs used to call the file.
In my case of 'python hello.py world', the system would pass ['hello.py','world'] as the argument for sys.argv. By creating a dictionary of callable functions, and then matching the string of the sys.argv with its respective function in the dictionary, I am able to execute the code as desired.
New code:
print('Hello')
def world():
print('Hello World')
import sys
callable_functions = {'world':world}
callable_functions[sys.argv[1]]()
Command prompt input and output now:
In: python hello.py world
Out: 'Hello'
Out: 'Hello World'