In this tutorial, we’ll learn how to create a list in Python using a while loop. A while loop is a control structure that allows us to repeat a block of code as long as a certain condition is true. Lists in Python are used to store multiple items in a single variable and can be accessed using indices.
Combining the while loop and list will allow us to dynamically create and manipulate the list based on certain conditions since the while loop provides greater control over the flow of code execution.
Step 1: Initialize an empty list and set up a condition variable
First, we need to initialize an empty list and declare a variable that will be used to control the while loop. This variable will be used in the condition of the while loop to determine if the code block inside the loop should be executed or not.
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my_list = [] counter = 0 |
Here, we’ve initialized an empty list called ‘my_list’ and a counter variable ‘counter’ that is initially set to 0.
Step 2: Create the while loop
Next, we’ll create the while loop with a condition that ends the loop when the counter variable reaches a certain value. Inside the loop, we’ll perform the desired actions to create our list.
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while counter < 5: # Code to add elements to the list will go here counter += 1 |
In this example, the loop will run until the counter variable is less than 5. Make sure to increment the counter variable inside the loop to avoid an infinite loop.
Step 3: Add elements to the list inside the while loop
Now, let’s add elements to our list inside the while loop. Depending on the desired output, we can use any expression to generate the elements for the list. In this example, we’ll simply append the values of the counter variable to the list.
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while counter < 5: my_list.append(counter) counter += 1 |
Here, we’re using the append() function to add elements to the list. As the loop iterates, the value of the counter variable is added to ‘my_list’, resulting in a list of numbers from 0 to 4.
Step 4: Print the resulting list
Once the while loop is done executing, we can print the resulting list to confirm that the elements have been added correctly.
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print("Created list: ", my_list) |
Full Code:
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my_list = [] counter = 0 while counter < 5: my_list.append(counter) counter += 1 print("Created list: ", my_list) |
Output:
Created list: [0, 1, 2, 3, 4]
Conclusion
In this tutorial, we learned how to create a list in Python using a while loop, which provides a versatile approach to populating and manipulating lists based on specific conditions.
This technique can be especially useful when working with dynamic or varying input values, such as user input or data from external sources like files or APIs.