Lesson 2 · Data analytics zero to hero

Python Control Flow: If, For & While Loops | Data Analytics #2

Video two of the 30-part series: making decisions and repeating work with if/else and loops. If you haven't seen video one on variables and data types,…

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CourseData analytics zero to hero
Lesson2 of 30
Video11 min
FormatJupyter notebook · 12 code cells

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Data Analytics Zero to Hero, Video 2: Control Flow#

Video two of the 30-part series: making decisions and repeating work with if/else and loops.
If you haven't seen video one on variables and data types, that's the natural starting point.
Let's jump straight in.

Before You Start#

Open a new Jupyter Notebook in VS Code and select your Python interpreter as the kernel.

Part 1: if, elif, and else#

score = 82
if score >= 70:
    print('Pass')

Pass

score = 55
if score >= 70:
    print('Pass')
else:
    print('Fail')

Fail

score = 75
if score >= 90:
    grade = 'A'
elif score >= 80:
    grade = 'B'
elif score >= 70:
    grade = 'C'
else:
    grade = 'D'
print(grade)

Part 2: for Loops#

prices = [19.99, 45.50, 12.75, 88.00]
for price in prices:
    print(price)

for i in range(5):
    print(i)

total = 0
prices = [19.99, 45.50, 12.75, 88.00]
for price in prices:
    total = total + price
print(f'Total: ${total:.2f}')

Total: $166.24

prices = [19.99, 45.50, 12.75, 88.00]
for index, price in enumerate(prices):
    print(f'Item {index}: ${price}')

Item 0: $19.99
Item 1: $45.5
Item 2: $12.75
Item 3: $88.0

Part 3: while Loops#

count = 0
while count < 5:
    print(count)
    count = count + 1

break and continue#

for number in range(10):
    if number == 5:
        break
    print(number)

for number in range(10):
    if number % 2 != 0:
        continue
    print(number)

Part 4: List Comprehensions#

prices = [19.99, 45.50, 12.75, 88.00]
discounted = [price * 0.9 for price in prices]
print(discounted)

[17.991, 40.95, 11.475, 79.2]

prices = [19.99, 45.50, 12.75, 88.00]
expensive = [price for price in prices if price > 20]
print(expensive)

[45.5, 88.0]

Wrap-Up: What You Learned#

if, elif, and else for branching logic based on conditions.
for loops for iterating over a sequence, plus enumerate for tracking position.
while loops for repeating until a condition changes, and why you must update that condition yourself.
break to exit a loop early, and continue to skip to the next pass.
List comprehensions for building and filtering lists in a single compact line.
Control flow is how your code makes decisions and does repeated work; video three covers functions and modules, so you can package this logic up and reuse it. Subscribe so it lands automatically see you there.

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