Writing to CSV files
Lesson details
Learning outcome
I can write data to a new file and append data to an existing text file.
Key learning points
- Writing to a CSV happens line-by-line in the same way as other text files.
- When writing to a CSV file you need to convert the data to a single string with commas used as separators.
- The join() method takes a list and returns a string.
Keywords
List - a dynamic data structure that can contain items of different data types
String - a sequence of characters, e.g. letters, numbers, spaces, and other symbols
Join() - the join method takes a list and joins each value in that list into one string
Common misconception
You can write integers directly to a CSV file using file.write(number).
All data must be converted to strings before writing.
Teacher tip
This lesson has a large section of slides that walk through a section of code. If you prefer, you could get pupils to run this code indvidually and record the values of the list in a trace table or on small whiteboards.
Equipment
Pupils will need access to a device that can edit and run Python programs. Examples in this lesson use the RPF Code Editor https://oak.link/python-editor
Licence
Lesson video
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Prior knowledge starter quiz
6 Questions
Q1.What does CSV stand for?
Q2.Each line in a CSV file is called a .
Q3.What method is used in Python to remove the character from a string?
Q4.The `split()` method turns a string into a .
Q5.What does this code do?
12line = "Aisha,0"
line = line.split(",")Code colour
Q6.Using `read()` will read the of a file into one string.
Assessment exit quiz
6 Questions
Q1.Each line in a CSV file represents a new or row.
Q2.Which error will this code produce?
123file = open("data.csv", "w")
file.write([1, 2, 3])
file.close()Code colour
Q3.To convert a list of integers to strings, you can use the () function inside a loop.
Q4.What does the .join() method do?
Q5.Match the function with its description.
convert a value to a string
combine list items into a string
save data to a file
Q6.To add a new row in a CSV file, you include the special character at the end of the string.
To help you plan your 11 computer science lesson on: Writing to CSV files, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your 11 computer science lesson on: Writing to CSV files, download all teaching resources for free and adapt to suit your pupils' needs.
The starter quiz will activate and check your pupils' prior knowledge, with versions available both with and without answers in PDF format.
We use learning cycles to break down learning into key concepts or ideas linked to the learning outcome. Each learning cycle features explanations with checks for understanding and practice tasks with feedback. All of this is found in our slide decks, ready for you to download and edit. The practice tasks are also available as printable worksheets and some lessons have additional materials with extra material you might need for teaching the lesson.
The assessment exit quiz will test your pupils' understanding of the key learning points.
Our video is a tool for planning, showing how other teachers might teach the lesson, offering helpful tips, modelled explanations and inspiration for your own delivery in the classroom. Plus, you can set it as homework or revision for pupils and keep their learning on track by sharing an online pupil version of this lesson.
Explore more key stage 4 computer science lessons from the Programming: dictionaries and data files unit, dive into the full secondary computer science curriculum, or learn more about lesson planning.