Uploading and reading csv file in Python

Question

I've got a program that reads and sorts information from a CSV file but I can't find out how to upload a file and either read it directly (which I don't think is possible) or upload it to a server.

Everything I try to Google either doesn't work or seems too ambiguous.

Has anyone got any idea how to upload the file from an HTML form so that I can read it in the program?

To read the file I'm using the csv module:

readerCTR = csv.reader(open("/home/ctrdata.csv", "rb"))

I'm using a really basic html form:

<form action="test" method="post" enctype="multipart/form-data">
Upload file: <input type="file" name="myfile" /> <br />
         <input type="submit" name="submit" value="Submit" />
</form>

and I've been trying to use the tutorial on CGI at docs.python

form = cgi.FieldStorage()
fileitem = form["myfile"]
if fileitem.file:
    linecount = 0
    while 1:
        line = fileitem.file.readline()
        if not line: break
        linecount = linecount + 1

but I just get key errors.

KeyError: 'myfile'

It seems like it isn't getting passed through at all. If I check the debugger:

>>> form
FieldStorage(None, None, [])

None of this makes ANY sense to me. I've never had to upload files before. I do have a server that I could save it to if I need to, but it would be ideal if I could just read it and temporarily save the data.

Do you think it could be that I'm using Firefox and Linux?

Answer 1

The problem with this was that I was using Pylons, so it was almost ignoring the CGI.

So instead I should have been using:

request.POST['myfile'].value

Answer 2

That you get the error means the upload works - sort of: Your CGI script is called but there is something wrong with the parameters. Steps to debug this:

1. Print the form.keys() to sys.stdout . That should give you a list of keys so you can check for typos.

2. Check the version of your cgi module. The documentation says

   and the latest addition is support for file uploads from a form

(my emphasis). Maybe your version is too old.