Module 24: Writing to Files

Learn how to save data for later use by writing it to files.

Anatomy of Writing a File

Click on each part of the code below. This pattern ensures files are handled safely. It's fundamental for I/O and Data Persistence.

with open('data.txt', 'w') as outfile:
    outfile.write("First line of data.\n")

Identify all parts!

Build-a-Write Statement

Drag the pieces into the dark grey area to construct a valid `with open(...)` statement that writes the text "Log Entry\n" to a file named `app.log` using write mode (`'w'`).

Drop pieces here...

File Writing Simulator

Type Python code in the editor to write to a simulated file named `sim_output.txt`. Use `with open('sim_output.txt', 'w') as f:` or `'a'` mode. The "Simulated File Content" area shows what *would* be in the file.

File content will appear here...

Match the Mode: 'w' vs 'a'

Choose the correct file opening mode (`'w'` for write/overwrite, `'a'` for append) for each scenario. Click your choice, then check.

File Writing Mini Missions!

Complete these coding tasks. The simulated output will show the content of `mission_log.txt`. Remember `\n` for new lines!

Mission 1: First Entry

Write the single line "System Initialized." (including the period and a newline `\n`) to `mission_log.txt`. Use `with` and write mode (`'w'`).

Mission 2: Add an Event

Append the line "User logged in." (including period and newline `\n`) to `mission_log.txt`. Use `with` and append mode (`'a'`). This should add to the previous content.

Mission 3: Multiple Lines, New File

Create a *new* file named `config.txt` (use write mode `'w'`). Write the following two lines exactly (each ending with `\n`):
`setting1=true`
`setting2=false`

Module 24 Practice Complete!

Great work! You've practiced writing data to files, a crucial skill for saving results and configurations.
Ready for more? Try the Advanced Practice for Module 24!