Repeat Code N Times in Python

1. Use a for Loop With the range() Function to Repeat N Times in Python
2. Use a while Loop to Repeat N Times in Python
3. Use the itertools.repeat() Function to Repeat N Times in Python
4. Use List Comprehension to Repeat N Times in Python
5. Use Recursion to Repeat N Times in Python
6. Conclusion

In Python, there are several ways to repeat a block of code a specific number of times, denoted as N. This operation is essential for tasks like iterating through sequences, implementing loops, or simulating scenarios.

In this tutorial, we will look into various methods to repeat the code N times in Python.

Use a for Loop With the range() Function to Repeat N Times in Python

The most common method to repeat a specific task or operation N times is using the for loop.

We can iterate the code lines N times using the for loop with the range() function in Python. The range(start, stop, step) function returns the sequence of numbers starting from the value specified in the start argument (equal to 0 by default) until the value specified in the stop argument.

The step argument specifies the step size of the sequence returned by the range() function, and its value is set to 1 by default.

The code example below demonstrates how to create a for loop with the range() method to repeat the code N times in Python.

# Number of times to repeat the code
N = 5

# Code block to be repeated
for _ in range(N):
    # Your code here
    print("Code block executed")

First, define the value of N, which represents the number of times you want to repeat the code. You can change this value to any positive integer.

Then, create a for loop that iterates over a range of numbers from 0 to N-1. In Python, range(N) generates numbers from 0 to N-1. _ is used as a throwaway variable in the loop.

Place the code block inside the loop that you want to repeat N times. In this example, we’ve used a simple print() statement for demonstration purposes. Replace it with your actual code.

Output:

Code block executed
Code block executed
Code block executed
Code block executed
Code block executed

Use a while Loop to Repeat N Times in Python

Another way to repeat code N times is using a while loop.

Here’s the complete code:

# Number of times to repeat the code
N = 5
count = 0

while count < N:
    # Your code here
    print("Code block executed")
    count += 1

First, set the value of N to the desired number of repetitions. Then, initialize a count variable to keep track of the number of iterations.

Use a while loop with the condition count < N to repeatedly execute the code block if the count is less than N.

Inside the loop, place the code block you want to repeat. Increment the count variable by 1 in each iteration to keep track of the number of repetitions.

Output:

Code block executed
Code block executed
Code block executed
Code block executed
Code block executed

Use the itertools.repeat() Function to Repeat N Times in Python

Python’s itertools module provides a convenient function called repeat() to repeat elements or code a specific number of times.

The itertools.repeat(val, num) method is an infinite iterator, which means it will iterate infinitely until the break statement if the num value (which represents the number of iterations) is not provided. This method’s val parameter represents the value printed on each iteration.

As we want to repeat the iteration N times, we will pass the value of N to the num argument and the None value to the val argument since we do not need to print anything.

The itertools.repeat() method is more efficient than the range() method, but the itertools module needs to be imported to use this method.

The code example below demonstrates the itertools.repeat() method to repeat a specific code N times.

from itertools import repeat

# Number of times to repeat the code
N = 5

# Your code here, enclosed in the repeat() function
for _ in repeat(None, N):
    print("Code block executed")

First, import the repeat() function from the itertools module and set the value of N to indicate how many times you want to repeat the code.

Use a for loop with repeat(None, N) to execute the code block N times. The None argument in repeat() is a placeholder, as the function is primarily designed for repeating elements.

Inside the loop, place the code block you want to repeat. We’ve used a print() statement in this example.

Output:

Code block executed
Code block executed
Code block executed
Code block executed
Code block executed

Use List Comprehension to Repeat N Times in Python

You can use list comprehension if you want to repeat the code to create a list of results. Here’s the code:

# Number of times to repeat the code
N = 5

# Your code here, enclosed in a list comprehension
results = ["Code block executed" for _ in range(N)]

# Printing the results (optional)
print(results)

First, define the value of N to specify how often you want to repeat the code.

Use a list comprehension to enclose the code block you want to repeat within square brackets. In this example, we’ve created a list called results containing the repeated code.

The _ variable is a common convention in Python for a loop variable not used within the loop. It represents a throwaway variable, indicating that you only want to repeat the code without using the loop variable.

Optionally, print the results list to see the repeated code blocks.

Output:

['Code block executed', 'Code block executed', 'Code block executed', 'Code block executed', 'Code block executed']

Use Recursion to Repeat N Times in Python

You can also achieve code repetition using recursion. Here’s the code:

# Number of times to repeat the code
N = 5

def repeat_code(count):
    if count < N:
        # Your code here
        print("Code block executed")
        repeat_code(count + 1)

# Start the repetition
repeat_code(0)

First, define the value of N to specify the desired number of repetitions.

Then, create a function called repeat_code that takes a count argument. This function will be responsible for executing the code block.

Inside the repeat_code function, use a base case to stop the recursion when the count reaches N. In each recursive call, execute the code block and increment the count by 1.

To start the repetition, call the repeat_code(0) function with an initial count of 0.

Output:

Code block executed
Code block executed
Code block executed
Code block executed
Code block executed

Conclusion

In this article, we’ve explored five methods to repeat code N times in Python: using for loops, while loops, the itertools.repeat() function, list comprehension, and recursion. Each method has its use cases and advantages, so choose the one that best fits your requirements and coding style.

Whether you’re iterating through sequences or simulating scenarios, these methods allow you to repeat code efficiently in your Python programs.