How to Repeat a String in Python?

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Introduction

Python is a versatile programming language for handling string data types and operations. String repetition is a common task in various programming and text manipulation tasks.

Whether you’re repeating a string for testing purposes or require formatting texts, Python offers various methods to repeat a string.

This guide covers different approaches to string repetition in Python through practical examples.

Prerequisites

Python 3 installed and configured (check the Python version before starting).
An IDE or text editor for Python.
(Optional) Python modules, such as Itertool functions, NumPy, or Pandas.

Repeat a String via * Operator

The simplest way to repeat a string in Python is with the * operator. Use the operator on a string to repeat the string a provided number of times.

The syntax for the operation is:

result = string * number

The code below demonstrates how to repeat the string “Hello, world!” five times:

result = "Hello, world!" * 5
print(result)

String repetition asterisk Python output

Alternatively, store the string and number in variables and change them as needed. For example:

my_string = "Hello, world!"
number = 5
result = my_string * number
print(result)

String repetition asterisk variables Python output

In both cases, the result is the string “Hello, world!” repeated five times.

Repeat a String via for Loop

Another built-in way to repeat a string in Python is using a for loop and the range function. Iterate over a provided range and append the string to a variable in each iteration.

The following code demonstrates the procedure to repeat a string five times:

result = ""

for _ in range(5):
  result += "Hello, world!"

print(result)

String repetition "for" loop Python output

The code does the following:

Creates an empty placeholder string variable result.
Goes through five iterations using the range(5) function.
Appends the provided string each time to the result variable using the += operator.
Prints the result to the console.

Note: The underscore in the for loop serves as a placeholder for the loop index variable.

To repeat a string and print on a new line each time, use the for loop and print the string:

for _ in range(5):
  print("Hello, world!")

Repeat string new line "for" loop Python output

The for loop repeats the print task five times and exits.

Repeat a String via itertools.repeat()

The itertools library contains various iteration functionalities for Python. The itertools.repeat() function creates an iterable object that repeats a string for a specified number of iterations. The syntax for the function is:

itertools.repeat(string, number)

The code below demonstrates how to use itertools.repeat() to repeat a string in Python:

import itertools
result = "".join(itertools.repeat("Hello, world!", 5))
print(result)

String repetition itertools.repeat() Python output

The code uses the join() method on an empty string to append the string iterable object to an empty string.

Alternatively, use the itertools.repeat() function in a for loop to repeat a string. For example:

import itertools
result = ""

for i in itertools.repeat("Hello, world!", 5):
  result+=i

print(result)

String repeat itertools.repeat() and "for" loop Python output

The itertools.repeat() function does not pre-generate the repeated values and is faster compared to the built-in range() function.

Repeat a String via numpy.repeat()

The NumPy library has various numerical functionalities, including object repetition. The numpy.repeat() function repeats a given object in a Python array. The syntax is:

numpy.repeat(string, number)

The operation result is an array with string elements. Join the array elements on an empty string to repeat a string using this method.

Note: This method requires installing NumPy.

The code below shows how to repeat a string via the numpy.repeat() function:

import numpy as np

result_array = np.repeat("Hello, world!", 5)
result = ''.join(result_array)
print(result)

Use the numpy.repeat() function when working with NumPy arrays or with array operations. When you are not working with arrays, use a simpler method to repeat a string.

Repeat a String for a Length With a User-Defined Function

If a code requires repeating different strings until a given string length, the most efficient approach is to create a custom function.

To create a function for repeating strings until a specified length, define the input and output variables. For example:

<b>input_string</b> and length – The string to be repeated and the length of the repetition are the input values.
result – The resulting repetition is the output value.

The code below demonstrates how to perform string repetition until a given length:

def repeat_length(input_string, length):

  number = int(length/len(input_string)+1)

  result = input_string * number

  print(result[:length])

repeat_length("Hello", 12)
repeat_length("World", 7)

Repeat string until length user function Python output

The repeat_length() function does the following:

There are two user-input variables, the string (input_string) and the length of the final string (length).
Line two determines the least number of repetitions necessary to get the correct number of characters.
In line three, the function repeats the string for the calculated number of times using the * operator.
Lastly, the function prints the result up to the provided length using string slicing.

Call the function and provide a string and length to test the results.

Conclusion

After reading this guide, you know several ways to repeat a string in Python. As each method provides different benefits, knowing different ways to perform the same task is beneficial.

Next, learn how to use Python substrings to get parts of a string.

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