No matter how careful you are in coding, it is easy to accidentally specify an incorrect encoding in a bytes object. For beginners and those learning little about Python, encoding is the conversion process of a string to a bytes object. On the other hand, decoding means the conversion process vice versa.

The following article focuses on discussing the best method to fix the error UnicodeDecodeError: ‘utf-8’ codec can’t decode byte 0xff in position 0: invalid start byte error with Python.

How To Fix The Error: UnicodedecodeError: ‘utf-8’ Codec Can’t Decode Byte 0xff In Position 0: Invalid Start Byte

Before learning more about different methods to solve the error, let’s clarify that it will likely happen during the string decoding process at a specific coding point.

The map of codings can deal with a small number of Unicode characters and str strings. For this reason, an illegal sequence of str characters or a non-ASCII sequence will lead to a failure in the coding-specific decode().

Python converts a byte array to a Unicode string to import and process a CSV file. This decoding process complies with the UTF-8 rules. However, there is every chance of a sequence of bytes that is forbidden in the strings. Here is an example:

Code:

import pandas as pd

a = pd.read_csv("filename.csv")

Output:

Traceback (most recent call last):

 UnicodeDecodeError: 'utf-8' codec can't decode byte 0x96 in position 2: invalid start byte

There are a wide range solutions for this issue, depending on the use cases. 

For Reading And Importing A CSV File Using Pandas

Pandas is one of the most widely used options to import and read a CSV file. If you run into the error when using this one, it would be best to employ the right encoding type. 

If you fail to find a suitable one, let’s set your current encoding to the unicode_escape:

import pandas as pd

data=pd.read_csv("C:\\Employess.csv",encoding=''unicode_escape')

print(data.head())

For JSON files

The error can also happen when you read and parse the content of a JSON file. This is because your JSON file is not formatted according to the UTF-8 rules. 

When loading this ISO-8859-1 file, try the encoding as follows to solve the issue:

json.loads(unicode(opener.open(...), "ISO-8859-1"))

For Other Formats 

With other formats, the only read mode is often specified, thus, making the decoding process improper. Such formats like logs can deal with the error if you open the binary file and continue reading the file. 

with open(path, 'rb') as f:

  text = f.read()

You can also use the decode() method to specify errors= ‘replace’:

with open(path, ‘rb’) as f:

  text = f.read().decode(errors='replace')

For The String Contents Decoding

For those encountering the error during the string variable reading, let’s use the encoding and turn it to a utf-8 format.

str.encode('utf-8').strip()

Conclusion

There are various approaches to fix the error: UnicodeDecodeError: ‘utf-8’ codec can’t decode byte 0xff in position 0: invalid start byte. Check the article above to get the best way for your case.