I'm trying to send a file via post request to server on localhost. I'm using HttpRequester in Firefox (also tried Postman in Chrome and Tasker on Android) to sumbit request.
The problem is that request.FILES is always empty. But when I try to print request.body it shows some non-human-readable data which particularly include the data from the file I want to upload (it's a database).  So it makes sense to me that somehow file arrives to the server.
From Django docs:

Note that FILES will only contain data if the request method was POST
  and the  that posted to the request had
  enctype="multipart/form-data". Otherwise, FILES will be a blank
  dictionary-like object.

There was an error 'Invalid boundary in multipart: None' when I tried to set Content-type of request to 'multipart/form-data'. An error disappeared when I added ';boundary=frontier' to Content-type.
Another approach was to set enctype="multipart/form-data".
Therefore I have several questions:

Should I use exactly multipart/form-data content-type?
Where can I specify enctype? (headers, parameters, etc)
Why the file's data contains in request.body but request.FILES is empty?

Thanks
Should I use exactly multipart/form-data content-type?


Django supports only multipart/form-data, so you must use that content-type.


Where can I specify enctype? (headers, parameters, etc)


in normal HTML just put enctype="multipart/form-data" as one of parameters of your form element. In HttpRequester it's more complicated, because I think it lacks support for multipart/form-data by default. http://www.w3.org/TR/html4/interact/forms.html#h-17.13.4.2 is more details about multipart/form-data, it should be possible to run it in HttpRequester by hand.


Why the file's data contains in request.body but request.FILES is empty?


You've already answered that:


Note that FILES will only contain data if the request method was POST and the that posted to the request had enctype="multipart/form-data". Otherwise, FILES will be a blank dictionary-like object.
Empty request.FILES in Django