In-memory I/O

Browser Python can't write to your disk — but it can write to memory with the same API.

io.StringIO / io.BytesIO

Behave just like a file object: .write(), .read(), .getvalue().

Why useful here

• Test code that expects a file handle
• Pipe between modules that all speak the file-object protocol (csv, json, gzip)

Try it

1. Write a JSON object to a StringIO and read it back with json.load.
2. Use csv.DictReader to parse the CSV above into a list of dicts.