Checking String input if Integer without Exception Handling

#This Python function checks String -typed (for I.E. User's Input through input-function found  @ Python Standard Library)
#if string is int -expression typed representing numbers in the range -2147483648 through 2147483647.

#Input parameter type String
#Return type Boolean

#Usage example:

#str = "";
#while (check(str) == False):
#   str = input("Please enter Integer value:");
#
#print(int(str));

#This function is alternative for using exception handling reserved keywords 'try' and 'except';

def check(str):

    if (len(str) >0) and isinstance(str(mjono),int):
        return True;
    return False;