UnicodeDecodeError, invalid continuation byte

I had the same error when I tried to open a CSV file by pandas.read_csvmethod.

The solution was change the encoding to latin-1:

pd.read_csv('ml-100k/u.item', sep='|', names=m_cols , encoding='latin-1')

In binary, 0xE9 looks like 1110 1001. If you read about UTF-8 on Wikipedia, you’ll see that such a byte must be followed by two of the form 10xx xxxx. So, for example:

>>> b'\xe9\x80\x80'.decode('utf-8')u'\u9000'

But that’s just the mechanical cause of the exception. In this case, you have a string that is almost certainly encoded in latin 1. You can see how UTF-8 and latin 1 look different:

>>> u'\xe9'.encode('utf-8')b'\xc3\xa9'>>> u'\xe9'.encode('latin-1')b'\xe9'

(Note, I'm using a mix of Python 2 and 3 representation here. The input is valid in any version of Python, but your Python interpreter is unlikely to actually show both unicode and byte strings in this way.)

It is invalid UTF-8. That character is the e-acute character in ISO-Latin1, which is why it succeeds with that codeset.

If you don't know the codeset you're receiving strings in, you're in a bit of trouble. It would be best if a single codeset (hopefully UTF-8) would be chosen for your protocol/application and then you'd just reject ones that didn't decode.

If you can't do that, you'll need heuristics.