I'm new to both zope and python, so I hope you'll forgive my ignorance. I'm writing a simple file upload web page. I've got it working most of the time; however when file names have certain characters in them I get errors like this: Zope Error Zope has encountered an error while publishing this resource. Error Type: Bad Request Error Value: The id "[X=X].foo" contains characters illegal in URLs. The code generating this error is as follows: origfilename=file.filename id=origfilename[max(string.rfind(origfilename, '/'), string.rfind(origfilename, '\\'), string.rfind(origfilename, ':'), )+1:] context.DemoArchive.manage_addFile(id,file, demo_title) I thought that using quote_url_plus would solve this, so I changed to: origfilename=file.filename id=origfilename[max(string.rfind(origfilename, '/'), string.rfind(origfilename, '\\'), string.rfind(origfilename, ':'), )+1:] id=url_quote_plus(id) context.DemoArchive.manage_addFile(id,file, demo_title) However I get the same error with the new string: The id "%5BX%3DX%5D.foo" contains characters illegal in URLs Can anyone tell me how to fix this please? TIA.