Dan Dan - 22 days ago 4
Python Question

Binary to String/Text in Python

I have searched many times online and I have not been able to find a way to convert my binary string variable, X

X = "1000100100010110001101000001101010110011001010100"


into a UTF-8 string value.

I have found that some people are using methods such as

b'message'.decode('utf-8')


however, this method has not worked for me, as 'b' is said to be nonexistent, and I am not sure how to replace the 'message' with a variable. Not only, but I have not been able to comprehend how this method works. Is there a better alternative?

So how could I convert a binary string into a text string?

EDIT: I also do not mind ASCII decoding

CLARIFICATION: Here is specifically what I would like to happen.

def binaryToText(z):
# Some code to convert binary to text
return (something here);
X="0110100001101001"
print binaryToText(X)


This would then yield the string...

hi


Thanks,
Daniel

Answer

It looks like you are trying to decode ASCII characters from a binary string representation (bit string) of each character.

You can take each block of eight characters (a byte), convert that to an integer, and then convert that to a character with chr():

>>> X = "0110100001101001"
>>> print(chr(int(X[:8], 2)))
h
>>> print(chr(int(X[8:], 2)))
i

Assuming that the values encoded in the string are ASCII this will give you the characters. You can generalise it like this:

def decode_binary_string(s):
    return ''.join(chr(int(s[i*8:i*8+8],2)) for i in range(len(s)//8))

>>> decode_binary_string(X)
hi

If you want to keep it in the original encoding you don't need to decode any further. Usually you would convert the incoming string into a Python unicode string and that can be done like this (Python 2):

def decode_binary_string(s, encoding='UTF-8'):
    bytes = ''.join(chr(int(s[i*8:i*8+8],2)) for i in range(len(s)//8))
    return bytes.decode(encoding)
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