Add binary_coded_decimal.py

bit_manipulation/binary_coded_decimal.py

@@ -0,0 +1,29 @@
+def binary_coded_decimal(number: int) -> str:
+    """
+    Find binary coded decimal (bcd) of integer base 10.
+    Each digit of the number is represented by a 4-bit binary.
+    Example:
+    >>> binary_coded_decimal(-2)
+    '0b0000'
+    >>> binary_coded_decimal(-1)
+    '0b0000'
+    >>> binary_coded_decimal(0)
+    '0b0000'
+    >>> binary_coded_decimal(3)
+    '0b0011'
+    >>> binary_coded_decimal(2)
+    '0b0010'
+    >>> binary_coded_decimal(12)
+    '0b00010010'
+    >>> binary_coded_decimal(987)
+    '0b100110000111'
+    """
+    return "0b" + "".join(
+        str(bin(int(digit)))[2:].zfill(4) for digit in str(max(0, number))
+    )
+
+
+if __name__ == "__main__":
+    import doctest
+
+    doctest.testmod()