This these files is a an incorrect way to import modules.

calc.py

# A primitive calcuator simulator

def multiply(num_1, num_2):
    """Returns the product of two numbers"""
    return num_1 * num_2

def add(num_1, num_2):
    """Returns the sum of two numbers"""
    return num_1 + num_2

result = multiply(3, 5)
print(f'Here is your result {result}')

main.py

  import calc