Printing a list vertically in Python

When working with lists in Python, sometimes you need to display elements vertically instead of the default horizontal format. This article explores three different approaches to print list elements in a vertical arrangement.

Basic List Structure

A Python list stores elements in square brackets and normally prints horizontally ?

fruits = ['apple', 'banana', 'cherry']
print(fruits)

['apple', 'banana', 'cherry']

Method 1: Using Simple For Loop

The most straightforward approach uses a for loop to print each element on a separate line ?

fruits = ['apple', 'banana', 'cherry']

for item in fruits:
    print(item)

apple
banana
cherry

Printing Nested Lists Vertically

For nested lists, use nested loops to print all elements vertically ?

nested_data = [[20, 40, 50], [79, 80], ["Hello"]]

for sublist in nested_data:
    for item in sublist:
        print(f"[{item}]")

[20]
[40]
[50]
[79]
[80]
[Hello]

Method 2: Using itertools.zip_longest()

The itertools.zip_longest() function handles lists of different lengths by filling missing values ?

import itertools

nested_data = [[20, 40, 50], [79, 80], ["Hello"]]

for row in itertools.zip_longest(*nested_data, fillvalue=" "):
    if any(item != " " for item in row):
        print(" ".join(str(item) for item in row))

20 79 Hello
40 80  
50   

Method 3: Using Class-Based Approach

You can encapsulate the vertical printing logic in a class for reusability ?

class VerticalPrinter:
    def __init__(self, data):
        self.data = data
    
    def print_vertical(self):
        for item in self.data:
            print(f"\t{item}")

# Usage
numbers = ['20', '40', '50', '79', '80', "Hello"]
printer = VerticalPrinter(numbers)
printer.print_vertical()

	20
	40
	50
	79
	80
	Hello

Comparison

Conclusion

Use simple for loops for basic vertical printing. Choose itertools.zip_longest() for complex nested structures, and class-based approaches when you need reusable, organized code.