Are you looking for the code to do it or understanding the algorithm?

Does this do what you need? Specifically a2b_uu and b2a_uu? There are LOTS of other options in there in case those aren't what you want.

(NOTE: Not a Python guy but this seemed like an obvious answer)

I'm not sure how you think you can do it other than character-by-character -- it's inherently a character-by-character operation. There is certainly code out there to do this for you, but there is no "simpler" way than doing it character-by-character.

First, you need to strip the 0b prefix, and left-zero-pad the string so it's length is divisible by 8, to make dividing the bitstring up into characters easy:

bitstring = bitstring[2:]
bitstring = -len(bitstring) % 8 * '0' + bitstring

Then you divide the string up into blocks of eight binary digits, convert them to ASCII characters, and join them back into a string:

string_blocks = (bitstring[i:i+8] for i in range(0, len(bitstring), 8))
string = ''.join(chr(int(char, 2)) for char in string_blocks)

If you actually want to treat it as a number, you still have to account for the fact that the leftmost character will be at most seven digits long if you want to go left-to-right instead of right-to-left.

For ASCII characters in the range [ -~] on Python 2:

>>> import binascii
>>> bin(int(binascii.hexlify('hello'), 16))
'0b110100001100101011011000110110001101111'

In reverse:

>>> n = int('0b110100001100101011011000110110001101111', 2)
>>> binascii.unhexlify('%x' % n)
'hello'

In Python 3.2+:

>>> bin(int.from_bytes('hello'.encode(), 'big'))
'0b110100001100101011011000110110001101111'

In reverse:

>>> n = int('0b110100001100101011011000110110001101111', 2)
>>> n.to_bytes((n.bit_length() + 7) // 8, 'big').decode()
'hello'

To support all Unicode characters in Python 3:

def text_to_bits(text, encoding='utf-8', errors='surrogatepass'):
bits = bin(int.from_bytes(text.encode(encoding, errors), 'big'))[2:]
return bits.zfill(8 * ((len(bits) + 7) // 8))


def text_from_bits(bits, encoding='utf-8', errors='surrogatepass'):
n = int(bits, 2)
return n.to_bytes((n.bit_length() + 7) // 8, 'big').decode(encoding, errors) or '\0'

Here's single-source Python 2/3 compatible version:

import binascii


def text_to_bits(text, encoding='utf-8', errors='surrogatepass'):
bits = bin(int(binascii.hexlify(text.encode(encoding, errors)), 16))[2:]
return bits.zfill(8 * ((len(bits) + 7) // 8))


def text_from_bits(bits, encoding='utf-8', errors='surrogatepass'):
n = int(bits, 2)
return int2bytes(n).decode(encoding, errors)


def int2bytes(i):
hex_string = '%x' % i
n = len(hex_string)
return binascii.unhexlify(hex_string.zfill(n + (n & 1)))

Example

>>> text_to_bits('hello')
'0110100001100101011011000110110001101111'
>>> text_from_bits('110100001100101011011000110110001101111') == u'hello'
True

This is my way to solve your task:

str = "0b110100001100101011011000110110001101111"
str = "0" + str[2:]
message = ""
while str != "":
i = chr(int(str[:8], 2))
message = message + i
str = str[8:]
print message

This is a spruced up version of J.F. Sebastian's. Thanks for the snippets though J.F. Sebastian.

import binascii, sys
def goodbye():
sys.exit("\n"+"*"*43+"\n\nGood Bye! Come use again!\n\n"+"*"*43+"")
while __name__=='__main__':
print "[A]scii to Binary, [B]inary to Ascii, or [E]xit:"
var1=raw_input('>>> ')
if var1=='a':
string=raw_input('String to convert:\n>>> ')
convert=bin(int(binascii.hexlify(string), 16))
i=2
truebin=[]
while i!=len(convert):
truebin.append(convert[i])
i=i+1
convert=''.join(truebin)
print '\n'+'*'*84+'\n\n'+convert+'\n\n'+'*'*84+'\n'
if var1=='b':
binary=raw_input('Binary to convert:\n>>> ')
n = int(binary, 2)
done=binascii.unhexlify('%x' % n)
print '\n'+'*'*84+'\n\n'+done+'\n\n'+'*'*84+'\n'
if var1=='e':
aus=raw_input('Are you sure? (y/n)\n>>> ')
if aus=='y':
goodbye()

if you don'y want to import any files you can use this:

with open("Test1.txt", "r") as File1:
St = (' '.join(format(ord(x), 'b') for x in File1.read()))
StrList = St.split(" ")

to convert a text file to binary.

and you can use this to convert it back to string:

StrOrgList = StrOrgMsg.split(" ")




for StrValue in StrOrgList:
if(StrValue != ""):
StrMsg += chr(int(str(StrValue),2))
print(StrMsg)

hope that is helpful, i've used this with some custom encryption to send over TCP.

Built-in only python

Here is a pure python method for simple strings, left here for posterity.

def string2bits(s=''):
return [bin(ord(x))[2:].zfill(8) for x in s]


def bits2string(b=None):
return ''.join([chr(int(x, 2)) for x in b])


s = 'Hello, World!'
b = string2bits(s)
s2 = bits2string(b)


print 'String:'
print s


print '\nList of Bits:'
for x in b:
print x


print '\nString:'
print s2

String:
Hello, World!


List of Bits:
01001000
01100101
01101100
01101100
01101111
00101100
00100000
01010111
01101111
01110010
01101100
01100100
00100001


String:
Hello, World!

Convert binary to its equivalent character.

k=7
dec=0
new=[]
item=[x for x in input("Enter 8bit binary number with , seprator").split(",")]
for i in item:
for j in i:
if(j=="1"):
dec=2**k+dec
k=k-1
else:
k=k-1
new.append(dec)
dec=0
k=7
print(new)
for i in new:
print(chr(i),end="")