In Python, a string (object of str class) is of immutable type. An immutable object is the one which can be modified in place, one created in the memory. Hence, unlike a list, any character in the sequence cannot be overwritten, nor can we insert or append characters to it unless we use certain string method that returns a new string object.
However, we can use one of the following tricks as a workaround to modify a string.
Converting a String to a List
Since both string and list objects are sequences, they are interconvertible. Hence, if we cast a string object to a list, modify the list either by insert(), append() or remove() methods and convert the list back to a string, to get back the modified version.
We have a string variable s1 with WORD as its value. With list() built-in function, let us convert it to a l1 list object, and insert a character L at index 3. The we use the join() method in str class to concatenate all the characters.
It will produce the following output −
original string: WORD ['W', 'O', 'R', 'L', 'D'] Modified string: WORLD
Using the Array Module
To modify a string, construct an array object. Python standard library includes array module. We can have an array of Unicode type from a string variable.
Items in the array have a zero based index. So, we can perform array operations such as append, insert, remove etc. Let us insert L before the character D
Now, with the help of tounicode() method, get back the modified string
It will produce the following output −
original string: WORD Modified string: WORLD
Using the StringIO Class
Python's io module defines the classes to handle streams. The StringIO class represents a text stream using an in-memory text buffer. A StringIO object obtained from a string behaves like a File object. Hence we can perform read/write operations on it. The getvalue() method of StringIO class returns a string.
Let us use this principle in the following program to modify a string.
It will produce the following output −
original string: WORD Modified string: WORLD
The End! should you have any inquiries, we encourage you to reach out to the Vercaa Support Center without hesitation.
