Logical operators in conditions in Python - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to check if a number is positive and less than 10.

Python

if num > 0 [1] num < 10:
    print("Number is between 1 and 9")

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

Aand

Bor

Cnot

Dxor

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'or' instead of 'and' which allows numbers outside the range.

Using 'not' which negates a condition incorrectly.

The and operator checks if both conditions are true.

2fill in blank

medium

Complete the code to check if a character is a vowel or a digit.

Python

if char in 'aeiou' [1] char.isdigit():
    print("It's a vowel or a digit")

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

Aand

Bxor

Cnot

Dor

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'and' which requires both conditions to be true.

Using 'not' which negates a condition incorrectly.

The or operator checks if either condition is true.

3fill in blank

hard

Fix the error in the condition to check if a number is not between 5 and 15.

Python

if num < 5 [1] num > 15:
    print("Number is outside 5 to 15")

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

Aand

Bor

Cxor

Dnot

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'and' which would never be true because a number can't be less than 5 and greater than 15 at the same time.

To check if a number is outside the range, use or between the two conditions.

4fill in blank

hard

Fill both blanks to create a dictionary of words with length greater than 3 and containing letter 'a'.

Python

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

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

A>

B<

Cand

Dor

Attempts:

3 left

💡 Hint

Common Mistakes

Using '<' instead of '>' for length comparison.

Using 'or' which includes words that don't meet both conditions.

We want words longer than 3 and containing 'a'.

5fill in blank

hard

Fill all three blanks to create a dictionary of uppercase keys and values for words longer than 4 or containing 'e'.

Python

result = [1]: [2] for word in words if len(word) [3] 4 or 'e' in word

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

Aword.upper()

Bword

C>

Dlen(word)

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'len(word)' as a key or value instead of the word itself.

Using '<' instead of '>' in the condition.

Keys are uppercase words, values are original words, and condition checks length > 4 or contains 'e'.

Practice

1. Which logical operator in Python means all conditions must be true for the whole expression to be true?

easy

A. xor

B. and

C. not

D. or

Solution

1. Step 1: Understand the meaning of 'and'

   The and operator returns true only if both conditions are true.

2. Step 2: Compare with other operators

   or needs only one true condition, not reverses truth, and xor is not a Python keyword.

3. Final Answer:

   and -> Option B

4. Quick Check:

   All conditions true = and [OK]

Hint: Remember: 'and' means all must be true [OK]

Common Mistakes:

• Confusing 'and' with 'or'
• Thinking 'not' means all true
• Using 'xor' which is not a Python keyword

2. Which of the following is the correct syntax to check if variable x is NOT equal to 10 and variable y is greater than 5?

easy

A. if x != 10 and y > 5:

B. if x <> 10 and y > 5:

C. if x != 10 & y > 5:

D. if x != 10 or y > 5:

Solution

1. Step 1: Check the inequality operator

   != is the correct 'not equal' operator in Python; <> is invalid syntax.

2. Step 2: Check logical operator usage

   and correctly combines two conditions; & is a bitwise operator and or changes logic.

3. Final Answer:

   if x != 10 and y > 5: -> Option A

4. Quick Check:

   Correct inequality and 'and' syntax [OK]

Hint: Use '!=' for not equal and 'and' to combine conditions [OK]

Common Mistakes:

• Using '<>' instead of '!='
• Using '&' instead of 'and'
• Using 'or' when 'and' is needed

3. What will be the output of this code?

age = 20
has_id = False
if age >= 18 and has_id:
    print('Allowed')
else:
    print('Denied')

medium

A. SyntaxError

B. Allowed

C. Denied

D. No output

Solution

1. Step 1: Evaluate each condition

   age >= 18 is True since 20 >= 18, but has_id is False.

2. Step 2: Apply 'and' operator

   True and False is False, so the else block runs.

3. Final Answer:

   Denied -> Option C

4. Quick Check:

   True and False = False [OK]

Hint: Both conditions must be true for 'and' to print Allowed [OK]

Common Mistakes:

• Assuming one True is enough with 'and'
• Confusing 'and' with 'or'
• Ignoring boolean value of variables

4. Find the error in this code snippet:

if not x > 10 or y < 5
    print('Check passed')

medium

A. Missing colon ':' after condition

B. Wrong use of 'not' operator

C. Incorrect indentation

D. Using 'or' instead of 'and'

Solution

1. Step 1: Check syntax of if statement

   Python requires a colon ':' at the end of the if condition line.

2. Step 2: Review other parts

   The use of not and or is correct; indentation is not shown as wrong here.

3. Final Answer:

   Missing colon ':' after condition -> Option A

4. Quick Check:

   if statements need ':' [OK]

Hint: Always put ':' after if condition [OK]

Common Mistakes:

• Forgetting ':' after if
• Misusing 'not' operator
• Wrong indentation without colon

5. You want to check if a number n is either less than 0 or greater than 100, but NOT equal to -10. Which condition correctly uses logical operators?

hard

A. if n < 0 or (n > 100 and n != -10):

B. if n < 0 and n > 100 or n != -10:

C. if not (n < 0 or n > 100) and n == -10:

D. if (n < 0 or n > 100) and n != -10:

Solution

1. Step 1: Understand the condition requirements

   We want numbers less than 0 or greater than 100, but exclude -10.

2. Step 2: Analyze each option

   if (n < 0 or n > 100) and n != -10: correctly groups the or condition and excludes -10 with and n != -10. if n < 0 or (n > 100 and n != -10): excludes -10 only when >100, not <0 (e.g., n=-10 is true). if not (n < 0 or n > 100) and n == -10: reverses logic and checks for equal -10. if n < 0 and n > 100 or n != -10: mixes and/or incorrectly.

3. Final Answer:

   if (n < 0 or n > 100) and n != -10: -> Option D

4. Quick Check:

   Group or, then exclude -10 with and [OK]

Hint: Group or conditions, then exclude with and [OK]

Common Mistakes:

• Wrong grouping of conditions
• Misplacing 'not' or 'and'
• Confusing '!=' with '=='