Parse CSV with Django and csv.DictReader

Question

I have a Django model with many fields (roughly 24), and apparently my users would like to be able to create instances of this object using a spreadsheet upload instead of manually entering all the data into forms.

I've found that using python's built in CSV module should make this fairly simple, but I'm having a hard time working out how exactly to use it.

Let's start out with what I have in terms of code:

def upload_file(request):

  if request.method == "POST":
    form = UploadFileForm(request.POST, request.FILES)
    if form.is_valid():
      handle_files(request.FILES['file'])
      return HttpResponseRedirect('/workflow/')
    else:
      print form.errors
      print request.FILES
      return HttpResponseRedirect('/workflow/upload')
  else:
    form = UploadFileForm()
    return render(request, 'fileform.html', {'formset': form})

This accepts a CSV file as an upload, and hands it off to handle_files to deal with the parsing and the object creation. This is the method I'm having trouble with.

def handle_files(f):
    reader = csv.DictReader(f, delimiter=' ', quotechar='|')
    ... #?

I've been trying to mimic the python docs (http://docs.python.org/2/library/csv.html), but DictReader is very poorly documented. Am I supplying csv.DictReader() the appropriate arguments? If I have, how can I get the information out of reader? I'm going to be supplying users with a template, so I can assume that each column of the CSV file has a predictable data. That is, I know that Column A will have data corresponding to field X, and column B corresponds to Y, etc. How do I go about parsing the data from the reader, and then creating an object with that data?

I'm guessing it will be something like:

for row in reader:
    X=row[1]
    Y=row[2]
    #etc
    my_object = MyObject(x=X, y=Y)
    my_object.save()

Is this way off? Should I be using another type of CSV reader?

Thanks for any help, I know there are a lot of questions in this post.

Answer 1

I've just recently started using Django but I've used the python csv library before. When I use it I just do the following:

import csv
...
reader = csv.reader(f)
for row in reader:
    #do something with each row
f.close()

So you were pretty close. Also, indexing starts at 0, so if you want the first element, use row[0].

There is more information on the csv library here. You only want to use delimiter and other parameters if the format of your file is different.

Answer 2

While creating the csv file, add the header:

people.csv

id  age  height
1   20   62
2   22   74
3   24   68

---

def handle_files(f):
    reader = csv.DictReader(open(f))
    for row in reader:
        id=row['id']
        age=row['age']
        height=row['height']
        my_object = MyObject(id=id, age=age,height=height)
        my_object.save()