Python HTTP Request Pitfall with JSON Parameters and a PDF‑Splitting Script Example

The author recently tested a new image‑upload service and discovered that the API expects a JSON‑formatted ctx parameter. When using Python's requests library, the URL is automatically percent‑encoded, corrupting the JSON string and causing the request to fail, whereas a raw curl call works correctly.

Investigation revealed that requests performs implicit URL encoding. The workaround is to avoid requests for such cases, use urllib2 (which does not auto‑encode), or manually encode the URL with urllib.parse.quote before sending.

After switching to urllib2 , the JSON payload is transmitted correctly and the API accepts the request.

In a separate anecdote, the author was asked by a girl to split a large PDF into individual pages. After trying various online tools without success, he wrote a short Python script using the PyPDF2 library to programmatically split the PDF, referencing the official documentation and contributing the source code.

The conclusion emphasizes that even popular libraries like requests can introduce subtle bugs, and developers should be aware of automatic encoding behavior when sending JSON parameters.