Added binary to base64 conversion (#12210)

Author: coolsidd

conversions/binary_to_base64.py

@@ -0,0 +1,120 @@
+"""
+* 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()