Lists and Loops
Pythons Tutorials
Lists
In Python, a list is a collection that stores multiple pieces of information. It’s like having a backpack that can hold various items.
1. Creating Lists and Accessing Elements:
Creating a list is as simple as putting items between square brackets, separated by commas. You can access individual items using their positions, called indices.
Example: Creating Lists and Accessing Elements
fruits = ["apple", "banana", "orange"]
print(fruits[0]) # Output: apple
print(fruits[2]) # Output: orange
2. Modifying Lists:
Lists are dynamic so you can add, remove, and even change items as you go along.
Example: Modifying Lists
# Adding an item to the end of the list
fruits.append("grape")
# Removing an item by value
fruits.remove("banana")
Loops:
Loops are your trusty sidekicks for performing repetitive tasks. There are different types of loops suited for different scenarios as shown below:
1. For Loops:
For loops help you dance through a set of actions for each item in a list, making repetitive tasks a breeze.
Example: Using a For Loop
Using the list of fruits we created earlier, let’s see the power of for loops.
for fruit in fruits:
print("I love", fruit + "s")
2. While Loops:
While loops keep performing actions as long as a certain condition is true.
Example: Using a While Loop
count = 0
while count < 5:
print("Count:", count)
count += 1
4. Range:
The range function and nested for loops give you control over how many times your actions repeat.
Example:
# Using range to repeat a task
for number in range(3):
print("Count:", number)5. Nested Loops:
Nested loops are like loops within loops.
Example: Nested For Loops
for x in range(3):
for y in range(2):
print("x:", x, "y:", y)