Pre-flight checklist automation in Drone Programming - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of battery check function

What is the output of this pre-flight battery check function when battery level is 75%?

Drone Programming

def check_battery(level):
    if level < 20:
        return "Battery too low"
    elif level < 50:
        return "Battery low"
    else:
        return "Battery sufficient"

print(check_battery(75))

A "Battery critical"

B "Battery low"

C "Battery too low"

D "Battery sufficient"

💡 Hint

Think about the battery level ranges and which message matches 75%.

The function returns "Battery sufficient" for levels 50 and above. Since 75 is above 50, it returns "Battery sufficient".

🧠 Conceptual

intermediate

Understanding sensor status check

If a drone's sensor status is represented by a dictionary {'GPS': True, 'Camera': False, 'Lidar': True}, which sensor is NOT ready for flight?

A Camera

B GPS

C Lidar

D All sensors are ready

💡 Hint

True means ready, False means not ready.

The 'Camera' sensor has a value False, meaning it is not ready for flight.

🔧 Debug

advanced

Identify the error in the checklist loop

What error does this code raise when running the pre-flight checklist loop? checklist = ['Battery', 'GPS', 'Camera'] for item in checklist print(f"Checking {item}...")

Drone Programming

checklist = ['Battery', 'GPS', 'Camera']
for item in checklist
    print(f"Checking {item}...")

A TypeError: 'list' object is not callable

B SyntaxError: expected ':' after for loop

C IndentationError: unexpected indent

D NameError: checklist is not defined

💡 Hint

Check the syntax of the for loop header.

The for loop is missing a colon ':' at the end of the line, causing a SyntaxError.

📝 Syntax

advanced

Correct dictionary comprehension for sensor readiness

Which option correctly creates a dictionary showing sensor readiness from a list of sensors with their status?

Drone Programming

sensors = [('GPS', True), ('Camera', False), ('Lidar', True)]

A {sensor: status for sensor, status in sensors if status == True}

B {sensor: status if status == True for sensor, status in sensors}

C {sensor: status for sensor, status in sensors if status}

D {sensor: status for sensor, status in sensors}

💡 Hint

Remember the syntax for filtering in dictionary comprehensions.

Option C correctly filters sensors with status True and creates the dictionary. Option C is invalid syntax, B is invalid, C includes all sensors regardless of status.

🚀 Application

expert

Final checklist status after automation run

Given this automation code, what is the final value of the variable 'ready' after running? checklist = {'Battery': True, 'GPS': True, 'Camera': False, 'Lidar': True} ready = all(checklist.values()) # What does 'ready' hold?

Drone Programming

checklist = {'Battery': True, 'GPS': True, 'Camera': False, 'Lidar': True}
ready = all(checklist.values())

A False

B None

C True

D Raises an error

💡 Hint

The all() function returns True only if all values are True.

Since 'Camera' is False, all(checklist.values()) returns False, so 'ready' is False.

Practice

1. What is the main purpose of automating a pre-flight checklist in drone programming?

easy

A. To improve safety and save time before flying

B. To make the drone fly faster

C. To change the drone's color automatically

D. To increase the drone's battery capacity

Solution

1. Step 1: Understand the goal of pre-flight checks

   Pre-flight checks ensure the drone is safe and ready to fly.

2. Step 2: Identify automation benefits

   Automating these checks saves time and reduces human error.

3. Final Answer:

   To improve safety and save time before flying -> Option A

4. Quick Check:

   Automation = Safety + Time saving [OK]

Hint: Think about safety and efficiency before flight [OK]

Common Mistakes:

• Confusing automation with drone speed
• Assuming automation changes hardware features
• Ignoring safety as the main goal

2. Which of the following is the correct way to define a class in drone programming for a pre-flight checklist?

easy

A. PreFlightCheck = {}

B. def PreFlightCheck(): pass

C. class PreFlightCheck: pass

D. function PreFlightCheck() {}

Solution

1. Step 1: Identify class syntax in drone programming (Python style)

   Classes are defined with the keyword 'class' followed by the name and colon.

2. Step 2: Check options for correct class definition

   class PreFlightCheck: pass uses 'class PreFlightCheck: pass' which is valid syntax.

3. Final Answer:

   class PreFlightCheck: pass -> Option C

4. Quick Check:

   Class keyword + name + colon = correct class [OK]

Hint: Classes start with 'class' keyword and colon [OK]

Common Mistakes:

• Using 'def' instead of 'class' for class definition
• Using curly braces instead of colon
• Assigning class to a dictionary

3. What will be the output of this code snippet?

class CheckList:
    def __init__(self):
        self.steps = {'battery': True, 'motors': True, 'gps': False}
    def all_passed(self):
        return all(self.steps.values())

check = CheckList()
print(check.all_passed())

medium

A. False

B. None

C. True

D. Error

Solution

1. Step 1: Analyze the steps dictionary values

   The steps are {'battery': True, 'motors': True, 'gps': False} so values are [True, True, False].

2. Step 2: Evaluate all() function on values

   all() returns True only if all values are True; here one is False, so result is False.

3. Final Answer:

   False -> Option A

4. Quick Check:

   all([True, True, False]) = False [OK]

Hint: all() returns False if any value is False [OK]

Common Mistakes:

• Assuming all() returns True if some values are True
• Confusing dictionary keys with values
• Expecting print to show dictionary instead of boolean

4. Identify the error in this pre-flight checklist code:

class PreFlight:
    def __init__(self):
        self.steps = {'battery': True, 'motors': True}
    def check_all(self):
        for step in self.steps:
            if self.steps[step] = False:
                return False
        return True

pf = PreFlight()
print(pf.check_all())

medium

A. Indentation error in for loop

B. Missing return statement in check_all method

C. Incorrect dictionary initialization syntax

D. Syntax error: '=' used instead of '==' in if condition

Solution

1. Step 1: Check the if condition syntax

   The line 'if self.steps[step] = False:' uses '=' which is assignment, not comparison.

2. Step 2: Correct syntax for comparison

   It should be '==' to compare values, so 'if self.steps[step] == False:' is correct.

3. Final Answer:

   Syntax error: '=' used instead of '==' in if condition -> Option D

4. Quick Check:

   Use '==' for comparison, '=' causes syntax error [OK]

Hint: Use '==' for comparison, not '=' [OK]

Common Mistakes:

• Using '=' instead of '==' in conditions
• Forgetting to return a value
• Misindenting loops or blocks

5. You want to extend the pre-flight checklist to automatically add a new step only if the drone has a camera. Which code snippet correctly adds this conditional step inside the class?

hard

A. self.steps['camera'] = self.has_camera

B. if self.has_camera == True:
self.steps['camera'] = True

C. self.steps['camera'] = True if self.has_camera else None

D. self.steps.append('camera') if self.has_camera else None

Solution

1. Step 1: Understand conditional addition of step

   We add 'camera' step only if self.has_camera is True.

2. Step 2: Check syntax for condition and dictionary update

   if self.has_camera == True: self.steps['camera'] = True uses 'if self.has_camera == True:' and sets self.steps['camera'] = True, which is clear and correct.

3. Final Answer:

   if self.has_camera == True: self.steps['camera'] = True -> Option B

4. Quick Check:

   Use if condition and dict assignment for conditional step [OK]

Hint: Use if condition with dict assignment for conditional steps [OK]

Common Mistakes:

• Using append on dictionary instead of assignment
• Assigning without condition
• Using wrong syntax for condition