<s>[INST] Python: 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

 [/INST] with positive integers you could use .isdigit:
>>> '16'.isdigit()
True

it doesn't work with negative integers though. suppose you could try the following:
>>> s = '-17'
>>> s.startswith('-') and s[1:].isdigit()
True

it won't work with '16.0' format, which is similar to int casting in this sense.
edit:
def check_int(s):
    if s[0] in ('-', '+'):
    	return s[1:].isdigit()
    return s.isdigit()

 </s>