If statement execution flow in Python - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to print 'Yes' if the number is greater than 10.

Python

number = 15
if number [1] 10:
    print("Yes")

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

A>

B<

C!=

D==

Attempts:

3 left

💡 Hint

Common Mistakes

Using '<' instead of '>' will check the wrong condition.

Using '==' checks equality, not greater than.

The condition should check if number is greater than 10, so we use the > operator.

2fill in blank

medium

Complete the code to print 'Even' if the number is divisible by 2.

Python

number = 8
if number [1] 2 == 0:
    print("Even")

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

A%

B//

C**

D+

Attempts:

3 left

💡 Hint

Common Mistakes

Using '//' gives the quotient, not the remainder.

Using '**' is for powers, not division.

The modulo operator % gives the remainder. If number % 2 == 0, the number is even.

3fill in blank

hard

Fix the error in the if statement to correctly check if x is not equal to 5.

Python

x = 7
if x [1] 5:
    print("Not five")

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

A==

B!=

C=

D<>

Attempts:

3 left

💡 Hint

Common Mistakes

Using '=' instead of '!=' causes a syntax error.

Using '<>' is not supported in Python 3.

The operator != means 'not equal to'. Using = is assignment, which causes an error here.

4fill in blank

hard

Fill both blanks to create a dictionary of words and their lengths, but only for words longer than 3 letters.

Python

words = ["apple", "cat", "banana", "dog"]
lengths = {word: [1] for word in words if len(word) [2] 3}

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

Alen(word)

B<=

C>

Dword

Attempts:

3 left

💡 Hint

Common Mistakes

Using '<=' includes words with length 3 or less.

Using 'word' instead of 'len(word)' gives the word itself, not its length.

We want the length of each word as the value, so use len(word). The condition should check if length is greater than 3, so use >.

5fill in blank

hard

Fill all three blanks to create a dictionary with uppercase keys and values only if the value is positive.

Python

data = {"a": 1, "b": -2, "c": 3}
result = [1]: [2] for k, v in data.items() if v [3] 0}

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

Ak.upper()

Bv

C>

Dk

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'k' instead of 'k.upper()' keeps keys lowercase.

Using '<' instead of '>' filters wrong values.

Keys should be uppercase, so use k.upper(). Values are v. The condition checks if v is greater than 0, so use >.

Practice

1. What does an if statement do in Python?

easy

A. It stores data in a list.

B. It repeats code multiple times.

C. It runs code only if a condition is true.

D. It defines a new function.

Solution

1. Step 1: Understand the purpose of if

   An if statement checks a condition and runs code only if that condition is true.

2. Step 2: Compare with other options

   Repeating code is done by loops, storing data is done by lists, and defining functions uses def.

3. Final Answer:

   It runs code only if a condition is true. -> Option C

4. Quick Check:

   if runs code if condition true [OK]

Hint: If checks condition; runs code only when true [OK]

Common Mistakes:

• Confusing if with loops
• Thinking if stores data
• Mixing if with function definition

2. Which of the following is the correct syntax for an if statement in Python?

easy

A. if x > 5 then:

B. if x > 5:

C. if (x > 5) {}

D. if x > 5 then

Solution

1. Step 1: Recall Python if syntax

   Python uses a colon : after the condition and no parentheses or 'then'.

2. Step 2: Check each option

   if x > 5: uses if x > 5: which is correct. Others use 'then' or braces which are not Python syntax.

3. Final Answer:

   if x > 5: -> Option B

4. Quick Check:

   Python if ends with colon [OK]

Hint: Python if ends with colon, no 'then' or braces [OK]

Common Mistakes:

• Adding 'then' after condition
• Using braces {} like other languages
• Forgetting the colon at the end

3. What will be the output of this code?

age = 20
if age < 18:
    print("Child")
elif age < 65:
    print("Adult")
else:
    print("Senior")

medium

A. Adult

B. Senior

C. Child

D. No output

Solution

1. Step 1: Check the value of age

   The variable age is 20.

2. Step 2: Evaluate conditions in order

   First condition age < 18 is false (20 is not less than 18). Second condition age < 65 is true (20 is less than 65), so it prints "Adult" and skips the else.

3. Final Answer:

   Adult -> Option A

4. Quick Check:

   20 is less than 65, prints Adult [OK]

Hint: Check conditions top to bottom; first true runs [OK]

Common Mistakes:

• Printing Child for age 20
• Ignoring elif and jumping to else
• Thinking no output if first condition false

4. Find the error in this code:

score = 75
if score >= 90
    print("Excellent")
elif score >= 60:
    print("Pass")
else:
    print("Fail")

medium

A. score variable not defined

B. Wrong indentation on print statements

C. Using elif instead of else if

D. Missing colon after first if condition

Solution

1. Step 1: Check syntax of if statement

   The first if line is missing a colon : at the end, which is required in Python.

2. Step 2: Verify other parts

   Indentation and elif usage are correct. The variable score is defined.

3. Final Answer:

   Missing colon after first if condition -> Option D

4. Quick Check:

   Every if needs a colon [OK]

Hint: Check colons after all if/elif/else lines [OK]

Common Mistakes:

• Forgetting colon after if condition
• Confusing elif with else if syntax
• Incorrect indentation of print lines

5. You want to print "Positive", "Zero", or "Negative" based on a number's value. Which code correctly uses if, elif, and else to do this?

hard

A. if num > 0:
print("Positive")
elif num == 0:
print("Zero")
else:
print("Negative")

B. if num > 0:
print("Positive")
if num == 0:
print("Zero")
else:
print("Negative")

C. if num > 0:
print("Positive")
else if num == 0:
print("Zero")
else:
print("Negative")

D. if num > 0:
print("Positive")
elif num < 0:
print("Zero")
else:
print("Negative")

Solution

1. Step 1: Understand correct if-elif-else structure

   Use if for first condition, elif for the second, and else for all other cases.

2. Step 2: Check each option

   if num > 0: print("Positive") elif num == 0: print("Zero") else: print("Negative") correctly uses elif and else. if num > 0: print("Positive") if num == 0: print("Zero") else: print("Negative") uses two separate if statements which can cause multiple prints. if num > 0: print("Positive") else if num == 0: print("Zero") else: print("Negative") uses invalid syntax else if. if num > 0: print("Positive") elif num < 0: print("Zero") else: print("Negative")'s elif num < 0 will print "Zero" for negative numbers and "Negative" for zero incorrectly.

3. Final Answer:

   if num > 0: print("Positive") elif num == 0: print("Zero") else: print("Negative") -> Option A

4. Quick Check:

   Use if, elif, else for exclusive conditions [OK]

Hint: Use if, elif, else for clear exclusive choices [OK]

Common Mistakes:

• Using multiple separate ifs causing multiple outputs
• Writing else if instead of elif
• Overlapping conditions causing wrong output