Python

Python Check If String is Number

If all of the characters in a string are numbers 0-9, the string is called a number string. “012345,” for example, is made up entirely of numeric characters, whereas “a12345” is not. This check determines whether str can be converted to an int. You can also determine whether or not a string represents an integer. There are various approaches to detecting whether a string is an integer.

While working on projects, we usually need to determine whether a particular Python string is an integer or not. As a result, you’ll learn about three typical ways for verifying whether a given python string is an integer or not in this article. So, without spending any time, let’s go right to the different examples to check if a string is an integer in Python.

Example 1:

We utilized Python’s isnumeric() method to determine whether or not a string is an integer in this example. The isnumeric() function is a built-in one. It returns True if all of the characters are numeric; otherwise, it returns False. The isnumeric() method does not require any parameters, hence string.isnumeric() is the syntax. In our first example, we used the isnumeric() method to verify if a string is an integer in three distinct ways. We’ve created and declared a string ‘a’ with the value ‘95644’ in the first example.

The isnumeric() method was then used to determine whether or not ‘95644’ is an integer. Because it is an integer in this example, it returned ‘True.’ we have again used a variable ‘a’ which is similar to the first, except that instead of declaring an integer value, we have merged integer and string values. The isnumeric() method will return False in this scenario.

Finally, we added some extra stages by combining the if-else and isnumeric() functions. Our variable ‘a’ was declared and initialized with the value ‘6581’. Then, using the isnumeric() function and flow control instructions, we identified whether or not the given string is an integer. It is an integer in this scenario. As a result, we’ll get an integer output. The result will be ‘Not an integer’ if the value is not an integer in any other case.

a='95644'

print(a.isnumeric())

a='program185'

print(a.isnumeric())

a='6581'

if a.isnumeric():

    print('Integer')

else:

    print('Not an integer')

When we run the code cited in the above image, we get the following appended result.

Example 2:

Using the exception handling mechanism in Python, we can check if the string is an integer. If you’re unfamiliar with how Python handles exceptions, here is a quick rundown. Exceptions in Python can easily be managed with the try statement. The try clause contains the crucial procedure that could result in exclusion. The except clause handles exceptions. As a result, after we’ve discovered the exclusion, we may choose which operations to perform.

You can understand how this method works with an example. We’ve created a string ‘a’ with the value ‘651ab’. At first glance, the value of string ‘a’ appears to be an integer. As a result, we declared it to be correct. After that, we converted a string to an integer with the int method. If the string ‘a’ contains non-numeric characters, ‘int’ will give a ValueError which indicates that the string is not an integer, and vice versa. We’ve also utilized flow control statements to print the results in conjunction with the exception-handling system.

a='651ab'

isInt=True

try:

    int(a)

except ValueError:

    isInt=False

if isInt:

    print('Integer')

else:

    print('Not an Integer')

To see the results, save and run the code.

Example 3:

Let’s have a look at an example of how this method works. The isdigit() function does not have any parameters. In our third example, we have extracted data from a string and saved it in the variable ‘my_str.’ After that, we checked whether the input text is an integer or not using control commands and the isdigit() function.

my_str=input("Please Insert Value:")

if my_str.isdigit():

    print("Integer")

else:

    print ("Not an Integer")

Upon executing the above code, you will get the following output.

Note: Only positive integer numbers will operate with the isdigit() method. i.e., any float number will be treated as a string if passed. It does not accept any parameters, therefore passing one will result in an error.

Conclusion:

Now you know the various ways to check if a string in Python is an integer. The easiest technique to check if a string is an integer in Python is determined by your requirements and the type of project you’re working on.

About the author

Kalsoom Bibi

Hello, I am a freelance writer and usually write for Linux and other technology related content