Logging to CSV files in Raspberry Pi - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to open a CSV file for writing.

Raspberry Pi

file = open('data.csv', '[1]')

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

A'w'

B'a'

C'r'

D'x'

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'r' mode instead of 'w' mode.

To write data to a CSV file, you open it in 'w' (write) mode.

2fill in blank

medium

Complete the code to import the module needed to write CSV files.

Raspberry Pi

import [1]

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

Acsv

Bjson

Cos

Dsys

Attempts:

3 left

💡 Hint

Common Mistakes

Importing unrelated modules like json or os.

The csv module helps to write and read CSV files easily.

3fill in blank

hard

Fix the error in the code to write a row to the CSV file.

Raspberry Pi

writer = csv.writer(file)
writer.[1](['time', 'temperature'])

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

Areadrow

Bwriteline

Cwritecsv

Dwriterow

Attempts:

3 left

💡 Hint

Common Mistakes

Using non-existent methods like 'writeline' or 'readrow'.

The correct method to write a single row is writerow.

4fill in blank

hard

Fill both blanks to open a CSV file and write a header row.

Raspberry Pi

with open('log.csv', [1], newline=[2]) as file:
    writer = csv.writer(file)
    writer.writerow(['date', 'value'])

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

A'w'

BTrue

C''

D'r'

Attempts:

3 left

💡 Hint

Common Mistakes

Using read mode 'r' or setting newline to True.

Open the file in write mode ('w') and set newline to '' to avoid extra blank lines on Windows.

5fill in blank

hard

Fill all three blanks to write multiple rows to a CSV file using a loop.

Raspberry Pi

with open('data.csv', [1], newline=[2]) as file:
    writer = csv.writer(file)
    for [3] in range(3):
        writer.writerow([f'Day {i+1}', i*10])

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

A'w'

B''

Ci

DTrue

Attempts:

3 left

💡 Hint

Common Mistakes

Using append mode instead of write, omitting newline='' causing blank lines, or wrong loop variable.

Open the file in write mode ('w'), set newline to '', and use 'i' as the loop variable.

Practice

1. What is the main reason to log data to a CSV file on a Raspberry Pi?

easy

A. To prevent the Raspberry Pi from overheating

B. To make the Raspberry Pi run faster

C. To install new software automatically

D. To store data in a simple table format that is easy to read and analyze

Solution

1. Step 1: Understand the purpose of CSV logging

   CSV files store data in rows and columns, making it easy to read and analyze later.

2. Step 2: Identify the benefit for Raspberry Pi logging

   Logging data in CSV helps keep records in a simple format without complex software.

3. Final Answer:

   To store data in a simple table format that is easy to read and analyze -> Option D

4. Quick Check:

   CSV logging = simple readable data [OK]

Hint: CSV files keep data organized in rows and columns [OK]

Common Mistakes:

• Thinking CSV speeds up the Raspberry Pi
• Confusing CSV logging with hardware functions
• Assuming CSV files install software

2. Which Python code snippet correctly opens a CSV file for appending new log entries on a Raspberry Pi?

easy

A. open('log.csv', 'r')

B. open('log.csv', 'w')

C. open('log.csv', 'a')

D. open('log.csv', 'x')

Solution

1. Step 1: Understand file modes in Python

   'r' is read-only, 'w' overwrites, 'a' appends, 'x' creates new file only if not exists.

2. Step 2: Choose mode to add logs without erasing old data

   Appending mode 'a' adds new lines at the end without deleting existing logs.

3. Final Answer:

   open('log.csv', 'a') -> Option C

4. Quick Check:

   Append mode = 'a' [OK]

Hint: Use 'a' mode to add data without erasing old logs [OK]

Common Mistakes:

• Using 'w' which erases existing file content
• Using 'r' which does not allow writing
• Using 'x' which fails if file exists

3. What will be the output in the CSV file after running this Python code on Raspberry Pi?

import csv
with open('log.csv', 'a', newline='') as file:
    writer = csv.writer(file)
    writer.writerow(['Time', 'Temperature'])
    writer.writerow(['10:00', '22'])

medium

A. A CSV file with two rows: header and one data row

B. An empty CSV file

C. A CSV file with only one row containing 'Time, Temperature, 10:00, 22'

D. A syntax error occurs

Solution

1. Step 1: Analyze the code writing rows to CSV

   The code writes two rows: first is header ['Time', 'Temperature'], second is data ['10:00', '22'].

2. Step 2: Understand CSV file content after appending

   Both rows are added as separate lines in the CSV file.

3. Final Answer:

   A CSV file with two rows: header and one data row -> Option A

4. Quick Check:

   Two rows written = header + data [OK]

Hint: Each writer.writerow adds one row to CSV [OK]

Common Mistakes:

• Thinking data merges into one row
• Expecting syntax errors from correct code
• Assuming file stays empty after writing

4. You run this code on your Raspberry Pi but the CSV file remains empty:

import csv
file = open('log.csv', 'w')
writer = csv.writer(file)
writer.writerow(['Date', 'Value'])
file.close()

What is the likely problem?

medium

A. The file was not closed properly

B. The newline parameter is missing in open() causing blank lines

C. The file was not opened in append mode

D. The writerow method was not called correctly

Solution

1. Step 1: Check file opening and writing

   File is opened in write mode and writerow is called correctly.

2. Step 2: Identify missing newline='' causing blank lines on Windows/Linux

   Without newline='', csv.writer may write extra blank lines or cause issues making file appear empty.

3. Final Answer:

   The newline parameter is missing in open() causing blank lines -> Option B

4. Quick Check:

   Use newline='' to avoid blank lines in CSV [OK]

Hint: Always use newline='' when opening CSV files for writing [OK]

Common Mistakes:

• Assuming append mode is required to write
• Forgetting to close the file (but here it is closed)
• Thinking writerow syntax is wrong

5. You want to log sensor data every minute on your Raspberry Pi into a CSV file without losing old data. Which Python code snippet correctly achieves this?

hard

A. import csv
with open('sensor_log.csv', 'a', newline='') as f:
writer = csv.writer(f)
writer.writerow(['12:01', '32'])

B. import csv
with open('sensor_log.csv', 'x', newline='') as f:
writer = csv.writer(f)
writer.writerow(['12:03', '33'])

C. import csv
with open('sensor_log.csv', 'r') as f:
writer = csv.writer(f)
writer.writerow(['12:02', '31'])

D. import csv
with open('sensor_log.csv', 'w', newline='') as f:
writer = csv.writer(f)
writer.writerow(['Time', 'Value'])
writer.writerow(['12:00', '30'])

Solution

1. Step 1: Identify file mode to keep old data

   Mode 'a' appends new data without erasing existing logs, perfect for ongoing logging.

2. Step 2: Check code correctness for logging new data

   Code opens file in append mode with newline='', writes one new row with time and value.

3. Final Answer:

   Code that appends new rows without deleting old data -> Option A

4. Quick Check:

   Append mode + newline='' = safe logging [OK]

Hint: Use 'a' mode and newline='' to add logs safely [OK]

Common Mistakes:

• Using 'w' mode which erases old logs
• Using 'r' mode which is read-only
• Using 'x' mode which fails if file exists