Logging to CSV files in Raspberry Pi - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a CSV file and why is it useful for logging?

A CSV (Comma-Separated Values) file stores data in plain text with values separated by commas. It is useful for logging because it is simple, easy to read, and can be opened by many programs like spreadsheets.

beginner

How do you write a new line of data to a CSV file in Python on a Raspberry Pi?

You open the file in append mode ('a'), then write a line with values separated by commas, ending with a newline character. For example: with open('log.csv', 'a') as f: f.write('value1,value2,value3\n')

beginner

Why should you open a CSV file in append mode when logging data continuously?

Append mode ('a') adds new data at the end of the file without deleting existing data. This keeps all previous logs intact while adding new entries.

intermediate

What Python module can help handle CSV files more safely and easily?

The 'csv' module in Python provides functions to read and write CSV files properly, handling commas inside data and quoting automatically.

intermediate

How can you include a timestamp in each log entry in a CSV file?

You can get the current time using Python's datetime module, then add it as a value in your CSV line. For example: from datetime import datetime; now = datetime.now().isoformat()

What file mode should you use to add new log entries to a CSV file without erasing old data?

A Append mode ('a')

B Write mode ('w')

C Read mode ('r')

D Exclusive creation mode ('x')

Append mode ('a') adds new data at the end of the file without deleting existing content.

Which Python module helps you write CSV files correctly, handling commas inside data?

A os

B json

C sys

D csv

The 'csv' module is designed to read and write CSV files properly.

What character usually separates values in a CSV file?

A Comma (,)

B Tab (\t)

C Space ( )

D Semicolon (;)

CSV stands for Comma-Separated Values, so commas separate the values.

How can you add the current date and time to each log entry in Python?

A Use the time.sleep() function

B Use datetime.now() from the datetime module

C Use print() function

D Use os.system()

datetime.now() gives the current date and time, which you can add to your log.

Why is logging to a CSV file helpful on a Raspberry Pi?

A Because CSV files are encrypted

B Because CSV files are binary and fast

C Because CSV files can be opened easily and are human-readable

D Because CSV files automatically upload to the cloud

CSV files are simple text files that can be opened by many programs and are easy to read.

Explain how to log sensor data to a CSV file on a Raspberry Pi using Python.

Think about how to add new lines without deleting old data and how to format the data.

Describe the benefits of using the Python csv module instead of writing CSV lines manually.

Consider what problems might happen if you write CSV lines as plain text.