```
"""Sum Even.

Usage: sum_even <number>...
"""
import sys


def sum_even(numbers):
    """Sum all the even numbers in a list."""
    assert isinstance(numbers, list), "numbers must be a list"

    total = 0
    for n in numbers:
        try:
            n_flt = float(n)
            if n_flt % 2 == 0:
                total += int(n_flt)  # it's an int if it's even, and python ints can be much larger than floats
        except ValueError:
            return f"{n} is not a number"
    return total


if __name__ == "__main__":
    numbers = sys.argv[1:]
    try:
        print(sum_even(numbers))
    except Exception as e:
        print(f"Could not sum all even numbers:\n {e}")
```
```
"""Sum Even.

Usage: sum_even <number>...
"""
import sys


def sum_even(numbers):
    """Sum all the even numbers in a list."""
    assert isinstance(numbers, list), "numbers must be a list"

    total = 0
    for n in numbers:
        try:
            n_flt = float(n)
            if n_flt % 2 == 0:
                total += int(n_flt)  # it's an int if it's even, and python ints can be much larger than floats
        except ValueError:
            return f"{n} is not a number"
    return total


if __name__ == "__main__":
    numbers = sys.argv[1:]
    try:
        print(sum_even(numbers))
    except Exception as e:
        print(f"Could not sum all even numbers:\n {e}")
```