Why data logging matters for IoT in Raspberry Pi - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to start logging sensor data to a file.

Raspberry Pi

with open('sensor_data.txt', '[1]') as file:
    file.write('Temperature: 22C\n')

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

Aa

Bx

Cw

Dr

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'w' erases existing data.

Using 'r' opens file for reading only.

Using 'a' opens the file in append mode, so new data is added without erasing existing data.

2fill in blank

medium

Complete the code to read the last line of the log file.

Raspberry Pi

with open('sensor_data.txt', 'r') as file:
    lines = file.readlines()
    last_line = lines[1]

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

A[:1]

B[0]

C[1]

D[-1]

Attempts:

3 left

💡 Hint

Common Mistakes

Using [0] gets the first line, not the last.

Using [:1] returns a list with the first line.

Using [-1] gets the last item from the list of lines.

3fill in blank

hard

Fix the error in the code to log data with a timestamp.

Raspberry Pi

import datetime
now = datetime.datetime.now()
with open('log.txt', 'a') as file:
    file.write(f"[1] - Sensor reading\n")

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

Adatetime.now()

Bnow.time()

Cnow.strftime('%Y-%m-%d %H:%M:%S')

Ddatetime.datetime()

Attempts:

3 left

💡 Hint

Common Mistakes

Using datetime.now() without import or formatting causes error.

Using now.time() gives only time, missing date.

Using now.strftime formats the datetime object into a readable string for logging.

4fill in blank

hard

Fill both blanks to create a dictionary logging temperature readings above 25 degrees.

Raspberry Pi

log = {sensor[1]: reading for sensor, reading in readings.items() if reading [2] 25}

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

A.upper()

B>

C<

D.lower()

Attempts:

3 left

💡 Hint

Common Mistakes

Using '<' filters wrong readings.

Not converting sensor names to uppercase.

We convert sensor names to uppercase and filter readings greater than 25.

5fill in blank

hard

Fill all three blanks to filter and log sensors with readings below 20 and convert sensor names to lowercase.

Raspberry Pi

filtered_log = [1]: [2] for [3], value in sensor_data.items() if value < 20}

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

Asensor.lower()

Bvalue

Csensor

Dreading

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'reading' instead of 'sensor' as loop variable.

Not converting sensor names to lowercase.

We use sensor.lower() as keys, value as values, and sensor as the loop variable.