本文からPOSTデータを読み取る

Unlike a plain GET, a POST request ships data in its body. Your view reads that body to learn what the client sent.

Most bodies are either an HTML form submission or a JSON payload from an API client. Flask offers a separate accessor for each.

When a browser submits a form, the values live in request.form, a dict-like object keyed by each field name.

Reading a missing key with brackets raises an error. Prefer request.form.get, which returns None when the field is absent.

Pass a second argument to get for a fallback value. It keeps your view working even when a field was left out.

API clients send JSON, not form fields. Call request.get_json to parse the body into a Python dictionary.

Flask reads the request's Content-Type header. Form fields need urlencoded data, while get_json expects application/json.

If the body is not valid JSON, get_json can return None. Pass silent=True to get None instead of an error you must catch.

Calling request.form on a JSON body gives you nothing. Match the accessor to how the client actually sent the data.

Uploaded files do not appear in request.form. They arrive in request.files, keyed by the file input's name.

Never trust the body blindly. Check that required keys exist and have sane values before you save or act on them.

Choose the right accessor for an API client.

Read form submissions with request.form.get and JSON payloads with request.get_json. Match the accessor to the Content-Type and validate. Solid! 👍