Please answer in Python (no imports, no list comprehension)

Write a function that takes in a filepath as a string and writes the number of uppercase and lowercase letters in the entire filepath to the file, in separate lines. This function should return None. Assume the filepath is always valid.

Hint: The filepath is just a string, and you could manipulate/do string operations as usual. The function str.isupper() might be helpful. The filepath provided is also the output file you should write to.

Note: The with open...print... in doctests opens the file you write in and checks if the content is correct. It does not hint towards the question itself.

Example: filepath = 'files/TEST.txt' In the given filepath, bold characters are upper and italic characters are lower, so output file should contain: 4 8

def case_letters(filepath): """ >>> case_letters('files/AlErNaTiNg.txt') >>> with open('files/AlErNaTiNg.txt', 'r') as outfile1: ... print(outfile1.read().strip()) 5 13 >>> case_letters('files/another_test.txt') >>> with open('files/another_test.txt', 'r') as outfile2: ... print(outfile2.read().strip()) 0 19 """