How can I check if a string represents an int, without using try/except?

Is there any way to tell whether a string represents an integer (e.g., '3', '-17' but not '3.14' or 'asfasfas') Without using a try/except mechanism?
is_int('3.14') == False
is_int('-7') == True


If you're really just annoyed at using try/excepts all over the place, please just write a helper function:

def represents_int(s):
    try: 
        int(s)
    except ValueError:
        return False
    else:
        return True

>>> print(represents_int("+123"))
True
>>> print(represents_int("10.0"))
False

It's going to be WAY more code to exactly cover all the strings that Python considers integers. I say just be pythonic on this one.

Stack Overflow Q#1265665, score: 517