Try and Except Structure in Python

The Python try…except statement catches an exception. It is used to test code for an error which is written in the “try” statement. If an error is encountered, the contents of the “except” block are run.

This is a way to eliminate or catch a traceback.

• We surround a dangerous section of code with try and except.

• If try works, then except is skipped

• If try fails to work, then the except section is executed.

Now, what is the dangerous section of code?

- It's the section where our code might blow up into some errors like traceback. For example, user input.

When we accept input from the users, they can enter any kind of values that may or may not be a problem for our code. To avoid situations like traceback, we often handle this using Try and Except structure.

#Here we are accepting a number from user.
num = input('Enter a number: ')
try:
    convert_num = int(num) # converting string into numeric
except:
    convert_num = -1
     
if convert_num >= 0:
    print('Nice work. You have entered ', convert_num)
else:
    print('Invalid Input')

Enter a number: 1234

Output:
Nice work. You have entered 1234

Enter a number: abcd

Output:
Invalid Input