UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position 5: ordinal not in range(128) code example

Example 1: 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 2: 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 3: Exception: 'ascii' codec can't decode byte 0xe2 in position 7860: ordinal not in range(128)

f = open(file_path, 'r+', encoding="utf-8")

Example 4: 'ascii' codec can't decode byte 0xc3 ordinal not in range(128)

f = open('../glove/glove.6B.100d.txt', encoding="utf-8")
#encoding is to changes the characters other text