print() parameters and formatting in Python - Mini Project: Build & Apply

Using print() Parameters and Formatting

📖 Scenario: You are creating a simple program to display a shopping list clearly on the screen. You want to control how the items appear by using different print() options.

🎯 Goal: Learn how to use the print() function's parameters like sep and end, and how to format output with f-strings.

📋 What You'll Learn

Create a list of shopping items

Set a separator string for printing items

Use a for loop to print items with the separator

Format and print a summary line using an f-string

💡 Why This Matters

🌍 Real World

Formatting output clearly is important when showing lists or reports in programs, like shopping lists or logs.

💼 Career

Understanding print formatting helps in debugging and creating user-friendly console applications.

1

Create a list of shopping items

Create a list called shopping_list with these exact items: 'apples', 'bananas', 'carrots', 'dates'

Python

# Create the list shopping_list with the items
# Your code here

Hint

Use square brackets [] and separate items with commas.

2

Set a separator string

Create a variable called separator and set it to the string ', ' (a comma followed by a space).

Python

shopping_list = ['apples', 'bananas', 'carrots', 'dates']
# Create the separator variable with the value ', '
# Your code here

Hint

Use quotes around the comma and space.

3

Print items using the separator

Use a for loop with variable item to go through shopping_list. Inside the loop, use print() to print each item followed by the separator without moving to a new line after each print.

Python

shopping_list = ['apples', 'bananas', 'carrots', 'dates']
separator = ', '
# Use a for loop to print each item with the separator without new lines
# Your code here

Hint

Use the end parameter of print() to avoid new lines.

4

Print a formatted summary line

After the loop, print a new line with the text Total items: 4 using an f-string and the len() function on shopping_list.

Python

shopping_list = ['apples', 'bananas', 'carrots', 'dates']
separator = ', '
for item in shopping_list:
    print(item, end=separator)
# Print the total number of items using an f-string
# Your code here

Hint

Use print(f"\nTotal items: {len(shopping_list)}") to start on a new line and show the count.

Practice

1. What does the sep parameter do in the print() function?

easy

A. It changes the separator between multiple items printed.

B. It changes the ending character of the printed line.

C. It formats numbers inside the print statement.

D. It pauses the program before printing.

Solution

1. Step 1: Understand the role of sep

   The sep parameter defines what string is placed between multiple items printed.

2. Step 2: Compare with other parameters

   end changes line ending, formatting is done by f-strings, and pausing is unrelated.

3. Final Answer:

   It changes the separator between multiple items printed. -> Option A

4. Quick Check:

   sep = separator [OK]

Hint: Remember: sep controls spacing between items [OK]

Common Mistakes:

• Confusing sep with end parameter
• Thinking sep formats numbers
• Assuming sep pauses output

2. Which of the following is the correct syntax to print two words separated by a dash using print()?

easy

A. print('hello' - 'world')

B. print('hello' + 'world', sep='-')

C. print('hello', 'world', end='-')

D. print('hello', 'world', sep='-')

Solution

1. Step 1: Identify correct use of sep

   Using sep='-' between multiple arguments prints them separated by a dash.

2. Step 2: Check syntax correctness

   print('hello', 'world', sep='-') uses correct syntax. print('hello' + 'world', sep='-') concatenates strings before printing, ignoring sep. print('hello', 'world', end='-') uses end, which changes line ending, not separator. print('hello' - 'world') is invalid syntax.

3. Final Answer:

   print('hello', 'world', sep='-') -> Option D

4. Quick Check:

   sep='-' joins words with dash [OK]

Hint: Use sep between items, not inside strings [OK]

Common Mistakes:

• Using + operator with sep parameter
• Confusing sep with end
• Trying to subtract strings

3. What is the output of this code?

print('A', 'B', 'C', sep='*', end='!')
print('D')

medium

A. A*B*C!D

B. A B C ! D

C. A*B*C
D

D. A B C!D

Solution

1. Step 1: Analyze first print()

   It prints 'A', 'B', 'C' separated by '*', ending with '!'. So output is 'A*B*C!'

2. Step 2: Analyze second print()

   It prints 'D' on the same line because first print ended with '!' (no newline).

3. Final Answer:

   A*B*C!D -> Option A

4. Quick Check:

   sep='*', end='!' joins and ends line [OK]

Hint: Remember end='' keeps output on same line [OK]

Common Mistakes:

• Assuming default space separator
• Thinking end adds newline
• Ignoring end parameter effect

4. The following code prints 'Score:-10'. What is the fix to print 'Score: 10'?

print('Score:', score, sep='-')

Assuming score = 10.

medium

A. Convert score to string before printing.

B. Change sep to end parameter.

C. Remove sep parameter or use it correctly between multiple items.

D. Add parentheses around score.

Solution

1. Step 1: Understand sep usage

   The sep='-' parameter places '-' between 'Score:' and score, resulting in 'Score:-10'.

2. Step 2: Identify the fix

   To print 'Score: 10' with default space separator, remove the sep parameter.

3. Final Answer:

   Remove sep parameter or use it correctly between multiple items. -> Option C

4. Quick Check:

   remove sep -> default space [OK]

Hint: Use sep only when printing multiple items [OK]

Common Mistakes:

• Confusing sep with end parameter
• Trying to convert variables unnecessarily
• Using sep with single string

5. How can you print the number 7.12345 rounded to 2 decimal places using print() and f-strings?

hard

A. print(f'{7.12345:2f}')

B. print(f'{7.12345:.2f}')

C. print(f'{7.12345:.2}')

D. print(f'{7.12345:.f2}')

Solution

1. Step 1: Understand f-string formatting

   To round a float to 2 decimals, use :.2f inside the braces.

2. Step 2: Check each option

   print(f'{7.12345:.2f}') uses correct syntax {value:.2f}. print(f'{7.12345:2f}') misses the dot before 2. print(f'{7.12345:.2}') uses wrong format specifier. print(f'{7.12345:.f2}') has incorrect order.

3. Final Answer:

   print(f'{7.12345:.2f}') -> Option B

4. Quick Check:

   Use .2f to round floats in f-strings [OK]

Hint: Use .2f inside f-string to round floats [OK]

Common Mistakes:

• Omitting the dot before precision
• Using wrong format specifiers
• Mixing order of letters and numbers