"Unicode Error "unicodeescape" codec can't decode bytes... Cannot open text files in Python 3

The problem is with the string

"C:\Users\Eric\Desktop\beeline.txt"

Here, \U in "C:\Users... starts an eight-character Unicode escape, such as \U00014321. In your code, the escape is followed by the character 's', which is invalid.

You either need to duplicate all backslashes:

"C:\\Users\\Eric\\Desktop\\beeline.txt"

Or prefix the string with r (to produce a raw string):

r"C:\Users\Eric\Desktop\beeline.txt"

Typical error on Windows because the default user directory is C:\user\<your_user>, so when you want to use this path as an string parameter into a Python function, you get a Unicode error, just because the \u is a Unicode escape. Any character not numeric after this produces an error.

To solve it, just double the backslashes: C:\\user\\<\your_user>...

Prefixing with 'r' works very well, but it needs to be in the correct syntax. For example:

passwordFile = open(r'''C:\Users\Bob\SecretPasswordFile.txt''')

No need for \\ here - maintains readability and works well.