binary_to_decimal converter (#2400)

* Create binary_to_decimal

binary to decimal converter

* Update conversions/binary_to_decimal

Co-authored-by: Christian Clauss <cclauss@me.com>

* Update binary_to_decimal

* Update conversions/binary_to_decimal

Co-authored-by: Christian Clauss <cclauss@me.com>

* Update binary_to_decimal

Co-authored-by: Christian Clauss <cclauss@me.com>

conversions/binary_to_decimal

@@ -0,0 +1,39 @@
+def bin_to_decimal(bin_string: str) -> int:
+    """
+    Convert a binary value to its decimal equivalent
+
+    >>> bin_to_decimal("101")
+    5
+    >>> bin_to_decimal(" 1010   ")
+    10
+    >>> bin_to_decimal("-11101")
+    -29
+    >>> bin_to_decimal("0")
+    0
+    >>> bin_to_decimal("a")
+    ValueError: Non-binary value was passed to the function
+    >>> bin_to_decimal("")
+    ValueError: Empty string value was passed to the function
+    >>> bin_to_decimal("39")
+    ValueError: Non-binary value was passed to the function
+    """
+    bin_string = str(bin_string).strip()
+    if not bin_string:
+        raise ValueError("Empty string was passed to the function")
+    is_negative = bin_string[0] == "-"
+    if is_negative:
+        bin_string = bin_string[1:]
+    if not all(char in "01" for char in bin_string):
+        raise ValueError("Non-binary value was passed to the function")
+    decimal_number = 0
+    for char in bin_string:
+        decimal_number = 2 * decimal_number + int(char)
+    if is_negative:
+        decimal_number = -decimal_number
+    return decimal_number
+
+
+if __name__ == "__main__":
+    from doctest import testmod
+
+    testmod()