Write Python code to find the largest number in a list.

You can find the largest number in a list by iterating through the list and keeping track of the maximum value seen so far. Here is a simple implementation:

def find_max(numbers):
    if not numbers:
        raise ValueError("List is empty")
    max_val = numbers[0]
    for num in numbers[1:]:
        if num > max_val:
            max_val = num
    return max_val

# Example usage
my_list = [3, 7, 2, 9, 4]
print(find_max(my_list))  # Output: 9

Python also provides a built‑in max() function that does the same in one line: max(numbers). The time complexity of the manual approach is O(n) because it examines each element once, and the space complexity is O(1) as only a few variables are used. This solution works for any comparable data type, not just integers.