Day 31/100: Enumerate, Zip, and Unpacking in Python

Welcome back to Day 31 of the 100 Days of Python journey!
Today, we dive into three powerful and often underused Python features that can make your code cleaner, shorter, and more expressive:

• enumerate()
• zip()
• Tuple unpacking

Let’s break each of these down with simple examples. 🧠

🔢 1. enumerate() – Get Index and Value in Loops

When looping through a list, you sometimes need both the index and the value.
Instead of using a range(len()) combo, use enumerate():

✅ Without enumerate():

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

for i in range(len(fruits)):
    print(i, fruits[i])

✅ With enumerate():

for index, fruit in enumerate(fruits):
    print(index, fruit)

🧪 Output:

0 apple
1 banana
2 cherry

You can even specify a custom starting index:

for i, fruit in enumerate(fruits, start=1):
    print(i, fruit)

🔗 2. zip() – Pairing Elements from Multiple Lists

The zip() function allows you to combine multiple iterables (like lists or tuples) element-wise.

✅ Example:

names = ['Alice', 'Bob', 'Charlie']
scores = [85, 92, 78]

for name, score in zip(names, scores):
    print(f"{name} scored {score}")

🧪 Output:

Alice scored 85
Bob scored 92
Charlie scored 78

⚠️ What if the lists have different lengths?

zip() stops at the shortest iterable.

a = [1, 2, 3]
b = ['x', 'y']

print(list(zip(a, b)))  # Output: [(1, 'x'), (2, 'y')]

To fill missing values, use itertools.zip_longest().

🎁 3. Unpacking – Split Values into Variables

Python lets you unpack values from lists, tuples, or zip results directly into variables.

✅ Example:

person = ("John", 25, "Engineer")
name, age, job = person

print(name)  # John
print(age)   # 25
print(job)   # Engineer

You can even unpack inside loops:

pairs = [(1, 'one'), (2, 'two'), (3, 'three')]

for number, word in pairs:
    print(f"{number} = {word}")

🎯 Bonus: Using _ to Ignore Values

If you want to ignore a value during unpacking:

data = ("Tom", 30, "Doctor")
name, _, profession = data

The underscore (_) is commonly used as a throwaway variable.

🔍 Why These Tools Matter

Using these tools makes your code more readable, less error-prone, and more Pythonic.

🧠 Practice Challenge

students = ['Emma', 'Liam', 'Olivia']
grades = [91, 88, 95]

# Task: Print "1. Emma scored 91" and so on...

Try solving this using enumerate() and zip() together!