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I need to convert an ASCII string into a list of bits and vice versa:
str = "Hi" -> [0,1,0,0,1,0,0,0,0,1,1,0,1,0,0,1] [0,1,0,0,1,0,0,0,0,1,1,0,1,0,0,1] -> "Hi" 
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Strings can be converted to lists using list() .
You can concatenate a list of strings into a single string with the string method, join() . Call the join() method from 'String to insert' and pass [List of strings] . If you use an empty string '' , [List of strings] is simply concatenated, and if you use a comma , , it makes a comma-delimited string.
To convert a string to list of characters in Python, use the list() method to typecast the string into a list. The list() constructor builds a list directly from an iterable, and since the string is iterable, you can construct a list from it.
Method#1: Using split() method The split method is used to split the strings and store them in the list. The built-in method returns a list of the words in the string, using the “delimiter” as the delimiter string.
There are many ways to do this with library functions. But I am partial to the third-party bitarray module.
>>> import bitarray >>> ba = bitarray.bitarray() Conversion from strings requires a bit of ceremony. Once upon a time, you could just use fromstring, but that method is now deprecated, since it has to implicitly encode the string into bytes. To avoid the inevitable encoding errors, it's better to pass a bytes object to frombytes. When starting from a string, that means you have to specify an encoding explicitly -- which is good practice anyway.
>>> ba.frombytes('Hi'.encode('utf-8')) >>> ba bitarray('0100100001101001') Conversion to a list is easy. (Also, bitstring objects have a lot of list-like functions already.)
>>> l = ba.tolist() >>> l [False, True, False, False, True, False, False, False, False, True, True, False, True, False, False, True] bitstrings can be created from any iterable:
>>> bitarray.bitarray(l) bitarray('0100100001101001') Conversion back to bytes or strings is relatively easy too:
>>> bitarray.bitarray(l).tobytes().decode('utf-8') 'Hi' And for the sake of sheer entertainment:
>>> def s_to_bitlist(s): ... ords = (ord(c) for c in s) ... shifts = (7, 6, 5, 4, 3, 2, 1, 0) ... return [(o >> shift) & 1 for o in ords for shift in shifts] ... >>> def bitlist_to_chars(bl): ... bi = iter(bl) ... bytes = zip(*(bi,) * 8) ... shifts = (7, 6, 5, 4, 3, 2, 1, 0) ... for byte in bytes: ... yield chr(sum(bit << s for bit, s in zip(byte, shifts))) ... >>> def bitlist_to_s(bl): ... return ''.join(bitlist_to_chars(bl)) ... >>> s_to_bitlist('Hi') [0, 1, 0, 0, 1, 0, 0, 0, 0, 1, 1, 0, 1, 0, 0, 1] >>> bitlist_to_s(s_to_bitlist('Hi')) 'Hi' If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
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