How to extract substring from a 'binary string' in python3

Question

I have a string b'helloworld\n'. I want to extract helloworld from it. For this, I am doing

print(string[1:-2])

But on output I am getting b'elloworl'.

How can I extraxt helloworld.

Thanks

`b` in front of string is a string literal which means string would of bytes type instead of `str` type and don't impact literal meaning of the string. See https://docs.python.org/3.3/reference/lexical_analysis.html#string-literals for more info. — apsdehal, Nov 09 '17 at 06:42
@apsdehal Thanks. I solved it using `string.decode("utf-8")` — S Andrew, Nov 09 '17 at 06:46

Antithesis · Answer 1 · 2017-11-09T06:44:33.063

4

print(s[0:-1])

Indexes are zero based so the h is at index zero. The ending index is non-inclusive, so go one extra.

If you want to get rid of the b you have to decode the bytes object.

print(s.decode('utf-8')[0:-1])

edited Nov 09 '17 at 06:44

answered Nov 09 '17 at 06:38

Antithesis

score 0 · Accepted Answer · answered Nov 09 '17 at 06:56

From this link, to change binary string to normal string use this:

>>> b'helloworld\n'.decode('ascii') # you can use utf8 or something else, it is up to you
'helloworld\n'

To delete whitespaces use strip():

>>> b'helloworld\n'.decode('ascii').strip()
'helloworld'

2 Answers2