[Zope] small python problem

[Dieter Maurer]

sanjeev c s writes:
 > i have a form which uploads a file.
 > and it calls a method which pass parameter to a python
 > script. this python script creates a 'file object'.
 > ....
 > if picture:
 >   container.foldername.manage_addImage(id=id,
 > file=picture)
 > 
 > but still even if the file is not uploaded the 'file
 > object' is created. what is the problem ??
The reason is easy:

  Even if no file is uploaded, you get a "FileUpload" object.

  Unfortunately, the "FileUpload" class does not define senseful
  "__len__" or "__nonzero__" methods (this is a
  bug --> <http:collector.zope.org>) and therefore, all such
  objects are considered Python true values.

Your options:

  *  Fix "ZPublisher.HTTPRequest.FileUpload" such that it
     defines a "__nonzero__" method. Post your patch to
     the collector (see above). This way, you help improve
     Zope

  *  Work around the problem in your application code.
     You can use:

	 "if picture.filename:" in place of "if picture:"


Dieter