sorted() function in Python - Mini Project: Build & Apply

Sorting a List of Fruits Alphabetically

📖 Scenario: You have a list of fruits that you want to organize alphabetically, just like arranging books on a shelf in order.

🎯 Goal: Learn how to use the sorted() function in Python to sort a list of items alphabetically.

📋 What You'll Learn

Create a list called fruits with the exact items: 'banana', 'apple', 'cherry', 'date'

Create a variable called sorted_fruits to store the sorted list

Use the sorted() function to sort the fruits list

Print the sorted_fruits list to show the result

💡 Why This Matters

🌍 Real World

Sorting lists is useful when you want to organize items like names, products, or any data alphabetically or by some order.

💼 Career

Many jobs require sorting data to make it easier to search, analyze, or display neatly, such as in data entry, programming, or report generation.

1

Create the list of fruits

Create a list called fruits with these exact items in this order: 'banana', 'apple', 'cherry', 'date'

Python

# Create the list called fruits with the given items
# Your code here

Hint

Use square brackets [] to create a list and separate items with commas.

2

Prepare a variable for the sorted list

Create a variable called sorted_fruits to hold the sorted list of fruits

Python

fruits = ['banana', 'apple', 'cherry', 'date']
# Create a variable sorted_fruits to store the sorted list
# Your code here

Hint

Just create an empty list variable for now; we will fill it next.

3

Sort the list using sorted()

Use the sorted() function to sort the fruits list and assign the result to sorted_fruits

Python

fruits = ['banana', 'apple', 'cherry', 'date']
sorted_fruits = []
# Use sorted() to sort fruits and assign to sorted_fruits
# Your code here

Hint

Call sorted(fruits) and assign it to sorted_fruits.

4

Print the sorted list

Print the sorted_fruits list to display the sorted fruits

Python

fruits = ['banana', 'apple', 'cherry', 'date']
sorted_fruits = sorted(fruits)
# Print the sorted_fruits list
# Your code here

Hint

Use print(sorted_fruits) to show the sorted list.

Practice

1. What does the sorted() function do in Python?

easy

A. Returns a new list with items arranged in order

B. Changes the original list to be sorted

C. Deletes all items from the list

D. Returns the largest item in the list

Solution

1. Step 1: Understand the purpose of sorted()

   The sorted() function creates a new list with the elements arranged in ascending order by default.

2. Step 2: Compare with other options

   It does not change the original list, nor does it delete items or return just the largest item.

3. Final Answer:

   Returns a new list with items arranged in order -> Option A

4. Quick Check:

   sorted() returns new sorted list [OK]

Hint: Remember: sorted() returns a new list, original stays same [OK]

Common Mistakes:

• Thinking sorted() changes the original list
• Confusing sorted() with max() or min()
• Assuming sorted() deletes items

2. Which of the following is the correct syntax to sort a list nums in reverse order using sorted()?

easy

A. sorted(nums, reverse=False)

B. sorted(nums, reverse=0)

C. sorted(nums, reverse=false)

D. sorted(nums, reverse=True)

Solution

1. Step 1: Check the correct parameter for reverse sorting

   The sorted() function uses the keyword argument reverse=True to sort in descending order.

2. Step 2: Validate the parameter type

   The value must be the boolean True, not False, numbers like 0, or undefined names.

3. Final Answer:

   sorted(nums, reverse=True) -> Option D

4. Quick Check:

   Use reverse=True (boolean) for descending sort [OK]

Hint: Use reverse=True (boolean), not False/0/undefined [OK]

Common Mistakes:

• Using reverse=False (sorts ascending)
• Passing falsy numbers like 0
• Using undefined lowercase 'false'

3. What is the output of the following code?

words = ['pear', 'apple', 'orange']
sorted_words = sorted(words, key=len)
print(sorted_words)

medium

A. ['pear', 'apple', 'orange']

B. ['pear', 'apple', 'orange'] sorted by length

C. ['apple', 'orange', 'pear']

D. ['pear', 'apple', 'orange'] sorted by length ascending

Solution

1. Step 1: Understand the key parameter

   The key=len tells sorted() to sort the list by the length of each word.

2. Step 2: Sort words by length

   Lengths: 'pear' (4), 'apple' (5), 'orange' (6). Sorted ascending by length: ['pear', 'apple', 'orange'].

3. Final Answer:

   ['pear', 'apple', 'orange'] -> Option A

4. Quick Check:

   sorted(words, key=len) sorts by length ascending [OK]

Hint: key=len sorts items by their length ascending [OK]

Common Mistakes:

• Confusing sorting by value vs length
• Assuming sorted() changes original list
• Misreading the order of output

4. Find the error in this code snippet:

numbers = [3, 1, 4, 1, 5]
sorted_numbers = sorted(numbers, key='abs')
print(sorted_numbers)

medium

A. sorted() cannot sort numbers

B. Missing parentheses after sorted

C. key argument should be a function, not a string

D. reverse argument is required

Solution

1. Step 1: Check the key argument type

   The key parameter must be a function, like abs, not a string.

2. Step 2: Identify the error

   Here, key='abs' is a string, which causes a TypeError.

3. Final Answer:

   key argument should be a function, not a string -> Option C

4. Quick Check:

   key needs a function, not string [OK]

Hint: Pass function to key, not string name [OK]

Common Mistakes:

• Passing string instead of function to key
• Thinking sorted() can't sort numbers
• Forgetting parentheses in function calls

5. You have a list of tuples representing people and their ages:

people = [('Alice', 30), ('Bob', 25), ('Charlie', 35), ('David', 25)]

How do you use sorted() to sort this list by age ascending, and if ages are equal, by name alphabetically?

hard

A. sorted(people, key=lambda x: (x[0], x[1]))

B. sorted(people, key=lambda x: (x[1], x[0]))

C. sorted(people, key=lambda x: x[1])

D. sorted(people, key=lambda x: x[0])

Solution

1. Step 1: Understand sorting by multiple criteria

   To sort by age first, then by name if ages tie, use a tuple key with age first, then name.

2. Step 2: Write the key function

   The lambda lambda x: (x[1], x[0]) returns a tuple (age, name) for sorting.

3. Step 3: Check other options

   The option sorting by name then age is incorrect. Options sorting by only one field are wrong.

4. Final Answer:

   sorted(people, key=lambda x: (x[1], x[0])) -> Option B

5. Quick Check:

   Use tuple key (age, name) for multi-level sort [OK]

Hint: Use tuple in key: (age, name) for multi-level sorting [OK]

Common Mistakes:

• Sorting by name before age
• Using single key instead of tuple
• Confusing tuple order in key function