TheAlgorithms/Python · error · TypeError

Input value must be an 'int' type

Error message

Input value must be an 'int' type

What it means

Raised by get_highest_set_bit_position when the argument is not an int. The function finds the highest set bit by right-shifting in a loop, which requires an integer operand; floats, strings, and None are rejected up front. Note: bool passes (subclass of int) and 0 is valid, returning 0.

Source

Thrown at bit_manipulation/highest_set_bit.py:21

    Returns position of the highest set bit of a number.
    Ref - https://graphics.stanford.edu/~seander/bithacks.html#IntegerLogObvious
    >>> get_highest_set_bit_position(25)
    5
    >>> get_highest_set_bit_position(37)
    6
    >>> get_highest_set_bit_position(1)
    1
    >>> get_highest_set_bit_position(4)
    3
    >>> get_highest_set_bit_position(0)
    0
    >>> get_highest_set_bit_position(0.8)
    Traceback (most recent call last):
        ...
    TypeError: Input value must be an 'int' type
    """
    if not isinstance(number, int):
        raise TypeError("Input value must be an 'int' type")

    position = 0
    while number:
        position += 1
        number >>= 1

    return position


if __name__ == "__main__":
    import doctest

    doctest.testmod()

View on GitHub (pinned to f5988cc097)

Solutions

1. Convert at the call site: get_highest_set_bit_position(int(x)) for whole-number floats.
2. For width of non-negative ints, prefer number.bit_length() which is idiomatic and faster.
3. Also guard number >= 0 yourself — this function's type check does not protect against negatives (infinite loop).

Example fix

# before
get_highest_set_bit_position(0.8)  # TypeError

# after
get_highest_set_bit_position(int(0.8))  # 0
# or better for n >= 0:
n.bit_length()

if not isinstance(number, int):
    number = int(number)
if number < 0:
    raise ValueError("must be non-negative (function loops forever otherwise)")

def is_int(value: object) -> bool:
    return isinstance(value, int) and not isinstance(value, bool)

When it happens

Trigger: Calling get_highest_set_bit_position(0.8), ('4',), or (None). Any non-int type raises; negative ints are NOT rejected and will loop forever — a separate pitfall.

Common situations: Passing float math results or parsed strings when computing bit widths for masks, encodings, or log2-style measurements.

Related errors

• Input value must be a 'int' type
• Both arguments MUST be integers!
• Input must be a non-negative integer
• Input must be a non-negative integer
• all elements must be integers

AI-assisted analysis of TheAlgorithms/Python@f5988cc097 (2026-08-14). Data as JSON: /api/errors/44261ad1f72afa8a. Report an issue: GitHub.