Given a string. The task is to write a regular expression to check whether a string starts and ends with the same character.
Input : abba Output : Valid Input : a Output : Valid Input : abc Output : Invalid
The input can be divide into 2 cases:
- Single character string: All single character strings satisfies the condition that they start and end with the same character. The regex for a string with only 1 character will be-
- Multiple character string: Here we need to check whether the first and the last character is same or not. We do this using
\1. The regex will be-
The two regular expressions can be combined using
In this program, we will use
search() method of re module.
Below is the implementation.
Valid Valid Invalid
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