How to deal with UnicodeDecodeError while reading a file?

Question

SNIPPET:

with open("sample.txt", 'r') as f:
filedata = f.read()

ERROR that I get: UnicodeDecodeError Traceback (most recent call last) in

  1 `with open("sample.txt", 'r') as f:`

----> 2 filedata = f.read() 3

C:\ProgramData\Anaconda3\lib\encodings\cp1252.py in decode(self, input, final)

 21 `class IncrementalDecoder(codecs.IncrementalDecoder):`
 22     `def decode(self, input, final=False):`

---> 23 return codecs.charmap_decode(input,self.errors,decoding_table)[0] 24 25 class StreamWriter(Codec,codecs.StreamWriter):

UnicodeDecodeError: 'charmap' codec can't decode byte 0x9d in position 1768: character maps to

Please help me to understand what is the cause of this error and how it can be solved. THANK YOU.