can't decode byte 0x99 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 0xa5 in position 10: invalid start byte

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