TheAlgorithms/Python · error · ValueError

numbers must be an iterable of integers

Error message

numbers must be an iterable of integers

What it means

Raised by minimum_subarray_sum(target, numbers) when numbers is not a list/tuple or contains non-int elements. Empty numbers returns 0 earlier, and target==0 present in numbers returns 0 before this check; otherwise the sliding-window algorithm requires an int sequence. Generators, strings, numpy arrays, and float-containing lists all fail.

Source

Thrown at dynamic_programming/minimum_size_subarray_sum.py:49

    >>> minimum_subarray_sum(-6, [])
    0
    >>> minimum_subarray_sum(-6, [3, 4, 5])
    1
    >>> minimum_subarray_sum(8, None)
    0
    >>> minimum_subarray_sum(2, "ABC")
    Traceback (most recent call last):
        ...
    ValueError: numbers must be an iterable of integers
    """
    if not numbers:
        return 0
    if target == 0 and target in numbers:
        return 0
    if not isinstance(numbers, (list, tuple)) or not all(
        isinstance(number, int) for number in numbers
    ):
        raise ValueError("numbers must be an iterable of integers")

    left = right = curr_sum = 0
    min_len = sys.maxsize

    while right < len(numbers):
        curr_sum += numbers[right]
        while curr_sum >= target and left <= right:
            min_len = min(min_len, right - left + 1)
            curr_sum -= numbers[left]
            left += 1
        right += 1

    return 0 if min_len == sys.maxsize else min_len

View on GitHub (pinned to f5988cc097)

Solutions

1. Coerce to a list of ints: minimum_subarray_sum(target, [int(x) for x in numbers]).
2. Use list(range(...)) rather than a raw range/generator.
3. Convert numpy inputs with .tolist().

Example fix

# before
length = minimum_subarray_sum(7, (int(x) for x in raw))  # generator -> ValueError

# after
length = minimum_subarray_sum(7, [int(x) for x in raw])

if not isinstance(numbers, (list, tuple)):
    numbers = list(numbers)
numbers = [int(n) for n in numbers]
length = minimum_subarray_sum(target, numbers)

def is_int_sequence(values: object) -> bool:
    return isinstance(values, (list, tuple)) and all(isinstance(v, int) for v in values)

try:
    length = minimum_subarray_sum(target, numbers)
except ValueError as exc:
    if 'iterable of integers' in str(exc):
        length = minimum_subarray_sum(target, [int(n) for n in numbers])
    else:
        raise

When it happens

Trigger: minimum_subarray_sum(2, 'ABC') as in the doctest; minimum_subarray_sum(7, [1.5, 2, 3]) with a float; passing a numpy array or map object as numbers.

Common situations: Sensor/metrics data arriving as floats; string inputs from stdin or web forms; feeding a range or generator directly instead of a list.

Related errors

• iterations must be defined as integers
• All weights must be integers but got weight of type {type(wt
• numbers must be an iterable of integers
• The parameter days should be a list of integers
• 'float' object cannot be interpreted as an integer

AI-assisted analysis of TheAlgorithms/Python@f5988cc097 (2026-08-14). Data as JSON: /api/errors/d8a657e498e0484a. Report an issue: GitHub.