UnicodeDecodeError: 'utf-8' codec can't decode byte

The UnicodeDecodeError occurs when Python tries to decode a byte sequence into Unicode using the 'utf-8' codec but encounters a byte that is not valid in the UTF-8 encoding. This error usually happens when working with text data that is not encoded properly or contains non-UTF-8 characters.


data = b'\xc3\x28' # Byte sequence containing invalid UTF-8 characters try: text = data.decode('utf-8') except UnicodeDecodeError as e: print("UnicodeDecodeError:", e) #Output: UnicodeDecodeError: 'utf-8' codec can't decode byte 0xc3 in position 0: invalid continuation byte

In this example, we have a byte sequence b'\xc3\x28'. The byte 0xc3 is not a valid starting byte for any UTF-8 character, and the decode() method fails to interpret it as a valid UTF-8 character, raising a UnicodeDecodeError.

Another common scenario where this error may occur is when reading text data from files without specifying the correct encoding:


file_path = 'data.txt' try: with open(file_path, 'r', encoding='utf-8') as file: content = file.read() except UnicodeDecodeError as e: print("UnicodeDecodeError:", e)

In this example, we are trying to read the content of a file 'data.txt' with the 'utf-8' encoding. If the file contains non-UTF-8 characters, the open() function will raise a UnicodeDecodeError.

To handle this error, you can do the following:
  1. Ensure that the data you are working with is properly encoded. If you encounter this error when reading data from files, verify that the file's encoding matches the one specified in the open() function (e.g., 'utf-8').
  2. If you are uncertain about the encoding of the data, you can try different codecs or use libraries like chardet to automatically detect the encoding.
  3. If you expect some data to be in a different encoding, you can handle the exception and attempt to decode it using the correct encoding explicitly.


Keep in mind that UnicodeDecodeError is a common issue when working with text data, and handling it properly is crucial for the smooth processing of data in Python.