Adding text over existing PDFs using reportlab

I'm interested in filling out existing PDF forms programatically. All I really need to do is pull information from user input and then place the appropriate text over an existing PDF in the appropriate locations. I can already do this with reportlab by feeding the same sheet of paper into a printer, twice, but this just really rubs me the wrong way.

I'm tempted to just personally reverse engineer each existing PDF and draw every line and character myself before adding the user-inputted text, but I wanted to check to see if there was an easy way to take an existing PDF and set it as a background for some extra text. I'd reall开发者_高级运维y prefer to use python as it's the only language I feel comfortable with.

I also realize that I could just scan the document itself and use the resulting raster image as a background, but I would prefer the precision of vector graphics.

It seems like ReportLab has a commercial product with this functionality, and the specific function I'm looking for is in it (copyPages) - but it seems like overkill to pay for a 4 figure product for a single, simple function for a nonprofit use.

If the PDF forms are real AcroForms you can use iText to fill them. I don't know if there's other port than iText (java, original) and iTextSharp (c#) but it's easy to use and free if you don't mind to open-source your solution. You can take a look at this sample code or (java snippet):

String formFile = "/path/to/myform.pdf"
String newFile = "/path/to/output.pdf"
PdfReader reader = new PdfReader(formFile);
FileOutputStream outStream = new FileOutputStream(newFile);
PdfStamper stamper = new PdfStamper(reader, outStream);
AcroFields fields = stamper.getAcroFields();

// fill the form
fields.setField("name", "Shane");
fields.setField("url", "http://stackoverflow.com");

// PDF infos
HashMap<String, String> infoDoc = new HashMap<String, String>();
infoDoc.put("Title", "your title here");
infoDoc.put("Author", "JRE ;)");
stamper.setMoreInfo(infoDoc);

// Flatten the PDF & cleanup
stamper.setFormFlattening(true);
stamper.close();
reader.close();
outStream.close();

If you just want to add some texts at a pre-printed paper. You can scan it as a jpg, then put this jpg as background. Please reference 15th page at reportlab manual, just call drawImage

It sounds like you just need to place an existing PDF in the background of a Reportlab PDF that you are generating. The free PDFRW library can do this easily. Take a look at the Example Tools page for some specific examples of this technique.