How to Input a List Into Python using a for Loop

In Python, data structures are a key aspect that every developer works with. One common task is to ingest a list of values for processing and analysis, and one versatile way to do this is with a for loop. This tutorial demonstrates how to harness the power of Python’s simple and efficient for loop to input a list.

Step 1: Understanding the Python List

A Python list is a built-in data type. Each item located in a list has an assigned index value. Each item in a list is separated by a comma and enclosed within square brackets. For example my_list = [1, 2, 3, 4]. Python makes it quite easy to input items into a list using a for loop.

Step 2: The For Loop in Python

The basic for loop in Python is used to iterate over items of any sequence such as a list or a string. In our case, it will be used to iterate over a list of input values and add each item to the list.

Step 3: Inputting a List Using a For Loop

To start off, here’s an example of inputting a list with 5 elements into Python using a for loop:

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n = 5
my_list = []
 
for i in range(0, n):
    ele = int(input())
    my_list.append(ele)
print(my_list)

Now we break down this code snippet:

  1. The first line defines a variable ‘n’ which specifies the number of elements in the next list.
  2. On the second line, we initialize an empty list my_list.
  3. Next, our for loop goes into action. It uses the range function to iterate ‘n’ times.
  4. During each iteration, an integer input is taken from the user and stored in the variable ‘ele’ (short for element).
  5. This element ‘ele’ is then appended to the list ‘my_list’ using the append() function, which adds an item to the end of a list.

After all ‘n’ elements have been entered by the user and appended to the list, Python will print out the entire list:

44
2
8
2
1
[44, 2, 8, 2, 1]

The Entire Code

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n = 5
my_list = []
 
for i in range(0, n):
    ele = int(input())
    my_list.append(ele)
 
print(my_list)

Conclusion

Python lists are extraordinarily flexible and can hold a mix of different data types, including other lists. The for loop provides a simple method for inputting items into a Python list. It is used to iterate over a sequence of inputs and append each item to the list. This tutorial aims to provide an understanding of Python list creation with user input using the for loop.