Why Can't I Decode \xdf (ß) Into Utf-8?

I have a bytestring b'\xDF'. When I try to decode it to UTF-8, a UnicodeDecodeError is thrown. Decoding to CP1252 works fine. In both charsets, 0xDF is represented by the character

Solution 1:

All single-byte encoded characters in UTF-8 have to be in the range [0x00 .. 0x7F] (https://en.wikipedia.org/wiki/UTF-8). Those are equivalent to 7-bit ASCII.

For the german ß, you'd get 2 bytes in UTF-8:

>>>"ß".encode("utf-8")

b'\xc3\x9f'

Which also works correctly when decoding:

b'\xc3\x9f'.decode("utf-8")

'ß'