UnicodeDecodeError: 'utf-8' codec can't decode byte 0xfd in position 42: invalid start byte code example

Example 1: 'utf-8' codec can't decode byte 0x85 in position 715: invalid start byte

import pandas as pd
data = pd.read_csv(filename, encoding= 'unicode_escape')

Example 2: UnicodeDecodeError: 'utf-8' codec can't decode byte 0xe9 in position 2892: invalid continuation byte

As suggested by Mark Ransom, I found the right encoding for that problem.
The encoding was "ISO-8859-1", so replacing

open("u.item", encoding="utf-8")
with
open('u.item', encoding = "ISO-8859-1")

will solve the problem.

Example 3: UnicodeDecodeError: 'utf-8' codec can't decode byte 0xb0 in position 1968: invalid start byte

pd.read_csv("C:/Users/Admin/Desktop/Python/Past.csv",encoding='cp1252')

Example 4: UnicodeDecodeError: 'utf-8' codec can't decode byte 0xa5 in position 10: invalid start byte

#use rb over r
with open(path, 'rb') as f:
  text = f.read()