Write a program that prints out a list of the integers from 1 to 20 and their squares. The output
should look like this: 
1 --- 1 
2 --- 4 
3 --- 9 
... 
20 --- 400 



for i in range(1, 21):
    print(f"{i} --- {i ** 2}")


This code will loop through the numbers 1 to 20, and for each iteration it will print the number followed by "---" and the square of the number. The ** operator is used to calculate the square of the number.

To run this code, you can save it to a file with a .py extension and run it using the python command in a terminal or command prompt.