# Repeat Code N Times in Python

Muhammad Waiz Khan Sep 22, 2023 Feb 14, 2021

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):
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:
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:
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.