Variable assignment in Python - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to assign the value 10 to the variable x.

Python

x = [1]

Drag options to blanks, or click blank then click option'

Ax

B'10'

C10

Dten

Attempts:

3 left

💡 Hint

Common Mistakes

Putting quotes around the number, which makes it a string.

Using the variable name instead of a value.

The variable x is assigned the number 10 without quotes because it is a number, not a string.

2fill in blank

medium

Complete the code to assign the string 'hello' to the variable greeting.

Python

greeting = [1]

Drag options to blanks, or click blank then click option'

A'hello'

Bhello

C"hello"

Dgreeting

Attempts:

3 left

💡 Hint

Common Mistakes

Not using quotes around the string.

Using the variable name instead of a string value.

Strings must be enclosed in quotes. Both single and double quotes work, so both options are correct.

3fill in blank

hard

Fix the error in the code to assign the sum of 5 and 3 to the variable total.

Python

total = 5 [1] 3

Drag options to blanks, or click blank then click option'

A+

B-

C*

D/

Attempts:

3 left

💡 Hint

Common Mistakes

Using subtraction or multiplication instead of addition.

Leaving out the operator.

The plus sign + adds two numbers together. Here, 5 + 3 equals 8.

4fill in blank

hard

Fill both blanks to assign the length of the word 'apple' to the variable length.

Python

length = [1]([2])

Drag options to blanks, or click blank then click option'

Alen

Bword

C'apple'

Dlength

Attempts:

3 left

💡 Hint

Common Mistakes

Using a variable name that is not defined.

Not using the length function.

The len() function returns the number of characters in a string. Here, it counts the letters in 'apple'.

5fill in blank

hard

Fill all three blanks to create a dictionary with keys as uppercase letters of words and values as their lengths, only for words longer than 3 letters.

Python

result = [1]: [2] for word in words if len(word) [3] 3}

Drag options to blanks, or click blank then click option'

Aword.upper()

Blen(word)

C>

Dword

Attempts:

3 left

💡 Hint

Common Mistakes

Using the word itself as key without uppercase.

Using wrong comparison operators.

Mixing keys and values.

This dictionary comprehension creates keys by converting each word to uppercase, values as the length of the word, and includes only words longer than 3 letters.

Practice

1. What does the following Python statement do?
age = 25

easy

A. Prints the value 25

B. Checks if age is equal to 25

C. Stores the value 25 in the variable named age

D. Deletes the variable age

Solution

1. Step 1: Understand the assignment operator

   The = sign in Python assigns the value on the right to the variable on the left.

2. Step 2: Analyze the statement age = 25

   This means the number 25 is stored inside the variable named age.

3. Final Answer:

   Stores the value 25 in the variable named age -> Option C

4. Quick Check:

   Assignment means storing value [OK]

Hint: Remember: '=' means store value, not compare [OK]

Common Mistakes:

• Confusing '=' with '==' for comparison
• Thinking '=' prints or deletes variables
• Assuming variable names are values

2. Which of the following is the correct way to assign the value 10 to a variable named count in Python?

easy

A. count == 10

B. count := 10

C. 10 = count

D. count = 10

Solution

1. Step 1: Identify the assignment operator

   In Python, the single equals sign = is used to assign values to variables.

2. Step 2: Check each option

   count == 10 uses == which is a comparison, not assignment. 10 = count tries to assign to a value, which is invalid. count := 10 uses walrus operator := which is valid in Python 3.8+, but not standard for simple assignment. count = 10 correctly assigns 10 to count.

3. Final Answer:

   count = 10 -> Option D

4. Quick Check:

   Use '=' for assignment [OK]

Hint: Use single '=' to assign values, not '==' [OK]

Common Mistakes:

• Using '==' instead of '=' for assignment
• Trying to assign value to a number
• Confusing walrus operator with assignment

3. What will be the output of this code?

name = "Alice"
age = 30
name = "Bob"
print(name, age)

medium

A. Alice 30

B. Bob 30

C. Alice 0

D. Bob 0

Solution

1. Step 1: Trace variable assignments

   Initially, name is set to "Alice" and age to 30. Then name is reassigned to "Bob".

2. Step 2: Understand print output

   The print statement outputs the current values of name and age. Since name was changed to "Bob", and age remains 30, the output is "Bob 30".

3. Final Answer:

   Bob 30 -> Option B

4. Quick Check:

   Last assignment wins [OK]

Hint: Last value assigned to variable is what prints [OK]

Common Mistakes:

• Thinking first assignment stays unchanged
• Confusing variable names or values
• Assuming age changes without assignment

4. Identify the error in this code snippet:

5number = 10
print(5number)

medium

A. Variable names cannot start with a number

B. Missing quotes around 5number

C. Assignment operator is wrong

D. print statement syntax error

Solution

1. Step 1: Check variable naming rules

   In Python, variable names must start with a letter or underscore, not a number.

2. Step 2: Analyze the code

   The variable name 5number starts with a digit, which is invalid syntax and causes an error.

3. Final Answer:

   Variable names cannot start with a number -> Option A

4. Quick Check:

   Variable names start with letter or underscore [OK]

Hint: Variable names cannot begin with digits [OK]

Common Mistakes:

• Starting variable names with numbers
• Confusing strings with variable names
• Assuming print syntax is wrong

5. You want to swap the values of two variables a and b in Python. Which of the following is the correct way to do it?

hard

A. a, b = b, a

B. a = b
b = a

C. temp = a
b = temp
a = b

D. a = a + b
b = a - b
a = a - b

Solution

1. Step 1: Understand swapping variables

   Swapping means exchanging values so that a gets b's value and b gets a's value.

2. Step 2: Analyze each option

   a = b b = a assigns b to a, then a to b, losing original a. temp = a b = temp a = b incorrectly assigns b before a. a = a + b b = a - b a = a - b uses arithmetic swap which works but is less clear and can cause errors with non-numbers. a, b = b, a uses Python's tuple unpacking to swap values correctly and clearly.

3. Final Answer:

   a, b = b, a -> Option A

4. Quick Check:

   Use tuple unpacking for swap [OK]

Hint: Swap with a, b = b, a for clean code [OK]

Common Mistakes:

• Overwriting variables before swapping
• Using temporary variable incorrectly
• Using arithmetic swap with non-numbers