For Loops

Basics of For Loop

100

What keyword starts a loop that iterates over each item in a sequence in Python?

for

200

In a for loop, what Python syntax indicates the start of the block of statements to repeat?

a colon (:) and indentation to start the block

300

Write the general form (using variable names) of a Python for loop that iterates over a sequence named seq. (Answer should be one line.)

for item in seq:

400

Explain in one short sentence why using a for loop is better than writing the same code multiple times

 It avoids repetition and reduces errors by running the same statements for each item automatically

500

Given a list called fruits = ["apple", "banana", "cherry"], what will this loop print?
for fruit in fruits:
print(fruit.upper())

APPLE
BANANA
CHERRY

range() Function

100

What built-in Python function is commonly used to generate a sequence of numbers for a for loop?

range()

200

What does range(5) produce as the sequence of integers (write them in order)?

0,1,2,3,40,1,2,3,4

300

How do you use range() to produce the numbers 2, 4, 6, 8? Write the exact range() call

range(2,9,2) or range(2,9,2)range(2,9,2) produces 2,4,6,8 (or more directly range(2,9,2)range(2,9,2)) — note: alternative range(2,9,2)range(2,9,2) uses stop 9 so 8 is last

400

What are the three arguments of range(start, stop, step)? Describe what each one does in one phrase

1. start = starting value, stop = one past the last value, step = increment between values.

500

Predict the list produced by list(range(1, 10, 3)). (Write the numbers in order.)

[1,4,7]

Practice Programs

100

In the guided practice example, what function is used to get user input (typed by the user) and convert it to an integer?

input() and int() — e.g., int(input("Enter a number: "))

200

The independent practice asks to create lists odd_numbers and even_numbers from 0 to 20. Which numbers (0, 1, 2, ...) should go into even_numbers? Give the first four even numbers from that range

Even numbers: 0, 2, 4, 6 (first four from 0 to 20

300

The sample solution uses for i in range(2,21,2) for even numbers. What is the role of the 21 in that call?

21 is the stop value (one past the last number to include 20).

400

Write a short program (4–6 lines) that creates an empty list called numbers, uses a for loop with range(5) to prompt the user to enter five integers, appends them, then prints the list. (Use the same style as the guided practice.)

Example: numbers = []
for i in range(5):
numbers.append(int(input("Enter a number: ")))
print(numbers)

500

Master challenge: Describe (in 2–3 sentences) how you would modify the program that separates odd and even numbers so that it also counts how many odd numbers and how many even numbers there are, and then prints those counts after printing the lists.

print("Even count:", len(even_numbers)) and print("Odd count:", len(odd_numbers)).