How to Check if a String Represents an Integer in Python Without Using Try/Except?

Checking String Representation of an Integer without Try/Except

Determining whether a given string represents an integer can prove tricky without resorting to exception handling. Here's how to navigate this challenge:

Using .isdigit() for Positive Integers

For positive integers, the .isdigit() method offers a straightforward solution:

'16'.isdigit()  # True

Handling Negative Integers

Negative integers require a bit more effort. We can check if the string starts with a minus sign and verify that the remaining characters consist of digits:

s = '-17'
s.startswith('-') and s[1:].isdigit()  # True

Excluding Floating-Point Numbers

Unfortunately, this approach falls short when dealing with floating-point numbers. For a comprehensive solution, we can consider the following function:

def check_int(s):
    if s[0] in ('-', '+'):
        return s[1:].isdigit()
    return s.isdigit()

This function allows for both positive and negative integers while excluding floating-point numbers. For instance:

check_int('3.14')  # False
check_int('-7')    # True

The above is the detailed content of How to Check if a String Represents an Integer in Python Without Using Try/Except?. For more information, please follow other related articles on the PHP Chinese website!