TheAlgorithms/Python · error · ValueError

maclaurin_sin() requires either an int or float for theta

Error message

maclaurin_sin() requires either an int or float for theta

What it means

Raised by maclaurin_sin() in maths/maclaurin_series.py when the theta argument is not an int or float. The function computes a Maclaurin series approximation of sin(theta), which requires a real numeric angle in radians. Any string, list, None, or other type is rejected before the series is evaluated.

Source

Thrown at maths/maclaurin_series.py:47

    Traceback (most recent call last):
        ...
    ValueError: maclaurin_sin() requires either an int or float for theta
    >>> maclaurin_sin(10, -30)
    Traceback (most recent call last):
        ...
    ValueError: maclaurin_sin() requires a positive int for accuracy
    >>> maclaurin_sin(10, 30.5)
    Traceback (most recent call last):
        ...
    ValueError: maclaurin_sin() requires a positive int for accuracy
    >>> maclaurin_sin(10, "30")
    Traceback (most recent call last):
        ...
    ValueError: maclaurin_sin() requires a positive int for accuracy
    """

    if not isinstance(theta, (int, float)):
        raise ValueError("maclaurin_sin() requires either an int or float for theta")

    if not isinstance(accuracy, int) or accuracy <= 0:
        raise ValueError("maclaurin_sin() requires a positive int for accuracy")

    theta = float(theta)
    div = theta // (2 * pi)
    theta -= 2 * div * pi
    return sum(
        (-1) ** r * theta ** (2 * r + 1) / factorial(2 * r + 1) for r in range(accuracy)
    )


def maclaurin_cos(theta: float, accuracy: int = 30) -> float:
    """
    Finds the maclaurin approximation of cos

    :param theta: the angle to which cos is found
    :param accuracy: the degree of accuracy wanted

View on GitHub (pinned to f5988cc097)

Solutions

1. Convert the argument before calling: maclaurin_sin(float(theta)).
2. Validate input at the boundary of your program (e.g. after argparse or JSON parsing) and coerce to float.
3. If you need Decimal/Fraction support, convert explicitly via float() since the check only accepts built-in int/float.

Example fix

# before
maclaurin_sin(raw_angle)  # raw_angle = '1.5'

# after
maclaurin_sin(float(raw_angle))

theta = float(theta) if not isinstance(theta, (int, float)) or isinstance(theta, bool) else theta

def is_valid_theta(x) -> bool:
    return isinstance(x, (int, float)) and not isinstance(x, bool)

When it happens

Trigger: Calling maclaurin_sin('1.5'), maclaurin_sin(None), maclaurin_sin([0.5]), or maclaurin_sin(Decimal('0.5')). Note that bool passes, since bool is a subclass of int in Python.

Common situations: Parsing angles from user input or config files as strings ('30' instead of 30), passing a numpy scalar or Decimal where a plain float is expected, or forwarding unvalidated data from JSON.

Related errors

• maclaurin_cos() requires either an int or float for theta
• maclaurin_sin() requires a positive int for accuracy
• maclaurin_cos() requires a positive int for accuracy
• Input must be an integer
• surface_area_cube() only accepts non-negative values

AI-assisted analysis of TheAlgorithms/Python@f5988cc097 (2026-08-14). Data as JSON: /api/errors/7ba711a2c0647b75. Report an issue: GitHub.