How to Use String Builder in Python?

Python String Builder

If you know StringBuilder in Java or C#, and want to learn how to use or get the String Builder equivalent for Python, this guide’s for you. Keep reading 👇

Most Java and C# programmers use String Builder in their code, but when they write programs in Python, they face the problems like how to use Python string builder in Python and what are the alternative options to String Builder in Python. 

In this article, we clear all your doubts about String Builder; we’ll discuss whether Python has any module name String Builder and if Python doesn’t have String Builder, what are the alternative options? But firstly, let’s discuss what a String Builder is.

So without any delay, let’s start solving the mystery of String Builder.



What is a String in Python?

Like many other languages, Python has a built-in string class named “str” with numerous handy methods. We can either enclose a string within a single or double quote. We can write string literals inside triple quotes if we want to write multiple lines of text. We can use backslash escapes within the string. 

For example.



print("This is a \n string ")



This is a 



In Python, strings are “immutable,” like in Java programming language. Immutable means we cannot change the string after we create it. A string is an array of bytes in Python; we don’t have a character datatype, but we can access a character within a string with the help of a square bracket[]

For example.



mystr= "This is a \n string."






As we write index 0, which represents the T character of mystr, and if we write index 1, it will represent the h character of mystr.



What is a String Builder in Java?

As we know, strings are immutable, so Java has a StringBuilder class which is mutable means we can create a changeable string with the help of the StringBuilder class. StringBuilder has many useful methods to change strings; some of them are append, reverse, insert and replace. Now let’s see an example to understand the working of StringBuilder in Java:



class Main{  

public static void main(String args[]){  

StringBuilder mysb=new StringBuilder(" This is a ");  

mysb.append("String");//append orignal string

System.out.println(mysb);//prints appended string 





This is a String



Do We Have String Builder in Python?

There is no built-in StringBuilder class in Python. Still, we can use some of its helpful methods to create a StringBuilder class that works like Java StringBuilder, or we can use built-in string functions directly to get the functionality of StringBuilder. We can use str.join() or io.StringIO to efficiently construct strings from multiple fragments.



What Are The Alternative of String Builder in Python?

Following are some alternative ways to get the functionality of StringBuilder in Python:

  1. Using Join Method
  2. Using String Concatenation
  3. Using the Concatenation Assignment Operator
  4. Using String IO Module
  5. Create Your Own String Builder Class



Method 1: Using The Join Method

We can use the built-in string function join to join two or more strings and add a separator between them. 

Its general syntax is:

stringVariable = Separator.join(str)


We assign a new string to stringVariable by joining a string variable with a separator. Here, the separator is another string; we can pass an array or string to the join function. Join is an iterable method that joins multiple strings into one string. Now understand the join method with the help of an example:



#Array of string

mystr = ("Zeshan", "Ali", "Asim") 

#Join array of string in single array

newstr = " ".join(mystr)        

#print new string on screen




Zeshan Ali Asim



Method 2: Using String Concatenation

We can concatenate the strings in Python with the ‘+‘ symbol; It is used to join two or more strings and assign them to any other string or print them. Now, understand how we can concatenate strings in Python:



# Initialize three string variables

mystr1 = "Zeshan"

mystr2 = "Ali"

mystr3 = "Asim"

#Join these strings in single string

newstr = mystr1 + mystr2 + mystr3      

#print new string on screen






We can add space between them by just concatenating ” “between strings. e.g.

newstr = mystr1 + “ “ + mystr2 + “ “ + mystr3



Method 3: Using Concatenation Assignment Operator

We can append one string with another string with the help of the concatenation assignment operator ‘+=‘. We can concatenate a string variable on the right after a string variable on the left. Now understand the working of this operator with the help of the following example:



# Initialize three string variables

mystr1 = "Zeshan"

# Appending string  

mystr1 += "Afridi"

#print a new string on the screen




Zeshan Afridi



Method 4: Using String IO Module

We can use the StringIO module to read and write strings. The getvalue() is used to get the string, and the write() method adds value to the string. Let’s understand this module with the help of an example:



from io import StringIO

# mystr is an array with three strings

mystr = ["Zeshan"," ", "Afridi"]

# an object of StringIO

ioString = StringIO()

for i in mystr:

# Write all strings in ioString one by one


# Print value of iostring on screen




Zeshan Afridi



Method 5: Create Your Own String Builder Class

We can create our own String Builder class, which we can use later in our projects. We create this class with the help of the StringIO module. Let’s have a look at our own String Builder Class and how it works:



from io import StringIO

# Create your own StringBuilder Class

class myStringBuilder:

    _f_str = None

    def __init__(self):

        self._f_str = StringIO()

    def Append(self, str):


    def __str__(self):

        return self._f_str.getvalue()

strBuilderObj = myStringBuilder()


strBuilderObj.Append(" ")





Zeshan Afridi




To conclude the article on String Builder in Python, we have seen we don’t have a native String Builder in Python, but we can use its functionality with the help of join(), concatenation operator, concatenation assignment operator, or StringIO module. Ultimately, it is our opinion to create your String Builder Class so you can easily use it in your other projects.

Let’s have a quick review of the topics discussed in this writing.

  1. What is a String?
  2. What is a String Builder in Java
  3. Do we have String Builder in Python?
  4. Alternative of String builder in Python

If this article is helpful and solves your puzzle, don’t forget to share it with your coding partners—also, comment below 🔽. Do you agree to have your own String Builder class in Python? 

 Happy coding! 😀



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