IndexError: string index out of range

This error occurs when you try to access an index of a string that does not exist. In other words, you are trying to access a character in a string at a position that is beyond the length of the string.

For example, if you have a string "hello" with length 5 and you try to access the character at index 5 (which is beyond the end of the string), you will get an IndexError.

To avoid this error, you should make sure that the index you are trying to access is within the range of the string. You can use the len() function to get the length of the string and then check if the index is within the range of 0 to length-1.