UnicodeDecodeError: 'charmap' codec can't decode byte X in position Y: character maps to <undefined>

This error occurs when trying to decode a string using the 'charmap' codec, which is typically used for Windows-1252 character encoding. The specific byte that is causing the error is indicated by the "X" in the error message and its position in the string is indicated by the "Y".

Here is an example of code that could trigger this error:

import codecs

# Attempt to decode a string using the 'charmap' codec
string = b'\x80This is a test string'
    decoded_string = codecs.decode(string, 'charmap')
except Exception as e:

# Output: 'UnicodeDecodeError: 'charmap' codec can't decode byte 0x80 in position 0: character maps to <undefined>'

In this example, the byte 0x80 is not a valid character in the Windows-1252 encoding and therefore causes the error. To fix this issue, you can try using a different codec or encoding that can handle the specific characters in the string.