Cannot open text files in Python 3: Unicode error

I am having a problem open a simple text file in Python 3.8. I setup a simple test.

Here is my test code:

import os

file_path = "c:UsersusernameDocumentsfolder1some_file.txt"

with open(file_path, 'r') as f:
    for line in f:
        print(line)

I get the following error: Unicode Error “unicodeescape” codec can’t decode bytes in position 2-3.

I have read other posts about putting an ‘r’ in front of the file path and when I do I get an “No such file or directory: ‘c:UsersusernameDocumentsfolder1some_file.txt’

import os

file_path = r"c:UsersusernameDocumentsfolder1some_file.txt"

with open(file_path, 'r') as f:
    for line in f:
        print(line)

I have also tried using double backslash in the path c:\Users\username\Documents\folder1\some_file.txt and that did not work either.