python - Converting byte string in unicode string

Question

I have a code such that:

a = "u0432"
b = u"u0432"
c = b"u0432"
d = c.decode('utf8')

print(type(a), a)
print(type(b), b)
print(type(c), c)
print(type(d), d)

And output:

<class 'str'> в
<class 'str'> в
<class 'bytes'> b'\u0432'
<class 'str'> u0432

Why in the latter case I see a character code, instead of the character? How I can transform Byte string to Unicode string that in case of an output I saw the character, instead of its code?

Answer 1

In strings (or Unicode objects in Python 2), u has a special meaning, namely saying, "here comes a Unicode character specified by it's Unicode ID". Hence u"u0432" will result in the character в.

The b'' prefix tells you this is a sequence of 8-bit bytes, and bytes object has no Unicode characters, so the u code has no special meaning. Hence, b"u0432" is just the sequence of the bytes ,u,0,4,3 and 2.

Essentially you have an 8-bit string containing not a Unicode character, but the specification of a Unicode character.

You can convert this specification using the unicode escape encoder.

>>> c.decode('unicode_escape')
'в'