![]() ![]() for i in range( 0, len(message_in_binary), out_byte_size):Ĭhunk = message_in_binary Typically we think of a byte as being composed of 8 bits representing a character and each byte representing a character. Next, we slice the total binary string representation into 6-bit chunks or bytes. This encoding causes an overhead of 33–37% (33% by the encoding itself up to 4% more by the inserted line breaks). The shorter the string, the worse the efficiency to a point. The efficiency will depend on the length of the string. That is a 3 times increase in characters. When converted to a Base64 string, it would be 4 characters long since. This is almost twice the size of the 12/7 ~= 1.71428 of the original binary representation. If we have 1 character each 7-bit long that is 1*7=7 bits and when converted to Base64 would be 2*6=12 bits since 7 bits wouldn't fit in 6 bits. Hence, the zfill(8) to get the 8-bit number representing each character in the message.īy doing this, we have increased the overall data. This looks to be ASCIIrepresentation since it is 7-bit long. Notice that even though python 3 strings are unicode, both the output is 7 bits long without the 0b prefix. For example ord('a') would output 97 which we would convert to binary with format(97, 'b') = 1100001: message_in_binary = "".join(format(ord(x), 'b').zfill(in_byte_size) for x in message)Ĭould use bin(), but that would yield 0b prefix to your string that represents the binary number. Take the message and convert it into binary by getting the code/int of an unicode character with ord. String.ascii_uppercase + string.ascii_lowercase + string.digits + string.digits + "+/" With Base64 we're converting any non-ASCII compliant characters or binary into a subset of the ASCII character set.Īfter refreshing up on the Base64 encoding, the first step was to create the corresponding character table: BASE64_CHARS = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/' Might as well write the encoder.Ĭause it's fun and the rabbit-holes. After finishing this problem, I thought it was a bit too easy and was compelled to redo it manually in python. ![]()
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