This content originally appeared on DEV Community and was authored by Sabin Sim
Day 6 – Loops (for / range)
Project: Build a “Multiplication Table Generator”
01. Learning Goal
By the end of this lesson, you will be able to:
- Understand how
forloops work in Python - Use the
range()function for numeric repetition - Combine loops with lists, strings, and nested loops
- Build a program that generates a multiplication table
02. Problem Scenario
You want to repeat actions automatically — for example,
printing every fruit in a basket or generating a multiplication table.
Manually typing each line is inefficient. Loops can automate this process.
03. Step 1 – What is a Loop?
A loop repeats a block of code multiple times.
In Python, there are two main types: for and while.
Today, we focus on for.
04. Step 2 – Basic for Loop
The for loop iterates over iterable objects such as lists, strings, or ranges.
fruits = ["apple", "banana", "grape"]
for f in fruits:
print(f)
Output:
apple
banana
grape
05. Step 3 – Using the range() Function
range() generates a sequence of numbers — commonly used for numeric loops.
# range(stop)
# range(start, stop)
# range(start, stop, step)
for i in range(5):
print(i) # 0, 1, 2, 3, 4
for i in range(1, 6):
print(i) # 1, 2, 3, 4, 5
for i in range(2, 11, 2):
print(i) # 2, 4, 6, 8, 10
06. Step 4 – Nested Loops
A loop can contain another loop — this is called a nested loop.
for i in range(2, 4): # 2, 3
for j in range(1, 4): # 1, 2, 3
print(i, "*", j, "=", i * j)
07. Step 5 – Looping Through Strings
Strings are also iterable, so each character can be processed individually.
for ch in "Python":
print(ch)
08. Step 6 – Practice Examples
Example 1: Sum of 1 to 10
total = 0
for i in range(1, 11):
total += i
print("Sum:", total)
Example 2: Multiplication Table (2 Times)
for i in range(1, 10):
print(f"2 x {i} = {2 * i}")
Example 3: Looping Through a List
names = ["Tom", "Anna", "Sabin"]
for n in names:
print(f"Hello, {n}!")
09. Step 7 – Mini Project: Multiplication Table Generator
Now create a program that prints any multiplication table the user requests.
dan = int(input("Enter a number to generate its table: "))
for i in range(1, 10):
print(f"{dan} x {i} = {dan * i}")
10. Reflection
You learned how to:
- Automate repetitive tasks using loops
- Iterate over lists, strings, and numeric sequences
- Use nested loops to handle structured patterns
- Build a functional Multiplication Table Generator
Next → Day 7 – While Loops & Mini Project
Learn how to repeat tasks based on conditions using the while loop.
This content originally appeared on DEV Community and was authored by Sabin Sim
Sabin Sim | Sciencx (2025-10-14T18:42:15+00:00) Python basics – Day 06. Retrieved from https://www.scien.cx/2025/10/14/python-basics-day-06/
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