Added binary to base64 conversion

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coolsidd 2024-10-20 19:09:26 +05:30
parent 03a42510b0
commit ad76b50db4

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"""
* Author: Siddharth Singh (https://github.com/coolsidd)
* Description: Convert a binary string to Base64.
References for better understanding:
https://en.wikipedia.org/wiki/Base64
"""
BITS_TO_B64 = {
"000000": "A",
"000001": "B",
"000010": "C",
"000011": "D",
"000100": "E",
"000101": "F",
"000110": "G",
"000111": "H",
"001000": "I",
"001001": "J",
"001010": "K",
"001011": "L",
"001100": "M",
"001101": "N",
"001110": "O",
"001111": "P",
"010000": "Q",
"010001": "R",
"010010": "S",
"010011": "T",
"010100": "U",
"010101": "V",
"010110": "W",
"010111": "X",
"011000": "Y",
"011001": "Z",
"011010": "a",
"011011": "b",
"011100": "c",
"011101": "d",
"011110": "e",
"011111": "f",
"100000": "g",
"100001": "h",
"100010": "i",
"100011": "j",
"100100": "k",
"100101": "l",
"100110": "m",
"100111": "n",
"101000": "o",
"101001": "p",
"101010": "q",
"101011": "r",
"101100": "s",
"101101": "t",
"101110": "u",
"101111": "v",
"110000": "w",
"110001": "x",
"110010": "y",
"110011": "z",
"110100": "0",
"110101": "1",
"110110": "2",
"110111": "3",
"111000": "4",
"111001": "5",
"111010": "6",
"111011": "7",
"111100": "8",
"111101": "9",
"111110": "+",
"111111": "/",
}
def bin_to_base64(bin_str: str) -> str:
"""Convert a binary value to its base64 equivalent
>>> bin_to_base64("000001")
'AB'
>>> bin_to_base64("0")
'A'
>>> bin_to_base64("1")
'B'
>>> bin_to_base64("-1")
'-B'
>>> bin_to_base64(" -000001 ")
'-AB'
>>> bin_to_base64("0-0")
Traceback (most recent call last):
...
ValueError: Non-binary value was passed to the function
>>> bin_to_base64("")
Traceback (most recent call last):
...
ValueError: Empty string was passed to the function
"""
bin_str = str(bin_str).strip()
if not bin_str:
raise ValueError("Empty string was passed to the function")
is_negative = bin_str[0] == "-"
if is_negative:
bin_str = bin_str[1:]
if not all(char in "01" for char in bin_str):
raise ValueError("Non-binary value was passed to the function")
bin_str = "0" * (6 * (divmod(len(bin_str), 6)[0] + 1) - len(bin_str)) + bin_str
base64_str = ""
while len(bin_str) > 0:
base64_str += BITS_TO_B64[bin_str[:6]]
bin_str = bin_str[6:]
return "-" + base64_str if is_negative else base64_str
if __name__ == "__main__":
from doctest import testmod
testmod()