将excel数据上传到django而不保存文件

Question

I am a newbie to django and i'm desperate for help uploading and reading excel data without actually saving the data on the machine. I have written some code and taken some from the research i've done online.

These are my questions:
1. How do I Upload an excel file (without it being saved on the machine). I just want the excel file to populate some django fields and not save it.

2. How do I make django read the columns in the excel file and feeds into some other fields on another page. (How do I link them up?)

3. Most docs I've seen require me to hard-code the name of the excel file and its locations.IS there a way around this as I don't know where the user might be uploading from. pls advice.

My views.py:

from django.shortcuts import render_to_response
from django.template import RequestContext
from django.http import HttpResponseRedirect
from django.core.urlresolvers import reverse
from credit.models import Document
from credit.forms import DocumentForm

def list(request):

if request.method == 'POST':
    form = DocumentForm(request.POST, request.FILES)
    if form.is_valid():

        newdoc = Document(docfile = request.FILES['docfile'])
        newdoc.save()

        return HttpResponseRedirect(reverse('credit.views.list'))
else:
    form = DocumentForm() 

documents = Document.objects.all()

return render_to_response('credit/list.html',
    {'documents': documents, 'form': form},
    context_instance=RequestContext(request)
)

My models.py is:

class Document(models.Model):
   docfile = models.FileField(upload_to='documents/')
#these are the models I want the excel columns to feed into
policies = DecimalNumberField()
capital = DecimalNumberField()
inflation = DecimalNumberField()

My forms.py is:

import os
import xlrd

IMPORT_FILE_TYPES = ['.xls', ]

class DocumentForm(forms.Form):
docfile = forms.FileField(label='Select a file')

def clean(self):
    data = super(DocumentForm, self).clean()

    if 'docfile' not in data:
        raise forms.ValidationError(_('The Excel file is required to proceed'))

    docfile = data['docfile']
    extension = os.path.splitext(docfile.name)[1]
    if not (extension in IMPORT_FILE_TYPES):
        raise forms.ValidationError(u'%s is not a valid Excel file. Please make sure your input file is an Excel file )' % docfile.name)

    file_data = StringIO.StringIO()
    for chunk in docfile.chunks():
        file_data.write(chunk)
    data['file_data'] = file_data.getvalue()
    file_data.close()

    try:
        xlrd.open_workbook(file_contents=data['file_data'])
    except xlrd.XLRDError, e:
        raise forms.ValidationError(_('Unable to open XLS file: %s' % e))

    return data
#i do not want to do this (specify the exact file name). Need an alternative   
sh = xlrd.open_workbook('documents\june.xls').sheet_by_index(1)
inflation = open("inflation.txt", 'w')
policies= open("policies.txt", 'w')
capital= open("access_to_finance.txt", 'w')

try:
    for rownum in range(sh.nrows):
        inflation.write(str(rownum)+ " = " +str(sh.cell(rownum, 1).value)+"\n")
        policies.write(str(rownum)+ " = " +str(sh.cell(rownum, 2).value)+"\n")
        capital.write(str(rownum)+ " = " +str(sh.cell(rownum, 3).value)+"\n")

finally:
    inflation.close()
    policies.close()
    capital.close()

Then I have a list.html file:

{% if documents %}
    <ul class="nav nav-tabs">
    {% for document in documents %}
        <li><a href="{{ document.docfile.url }}">{{ document.docfile.name }}</a></li>
    {% endfor %}
    </ul>
{% else %}
    <p>Click Upload to go to Upload page</p>
{% endif %}

     <form action="{% url list %}" method="post" enctype="multipart/form-data">
        {% csrf_token %}
        <p>{{ form.non_field_errors }}</p>
        <p>{{ form.docfile.label_tag }} {{ form.docfile.help_text }}</p>
        <p>
            {{ form.docfile.errors }}
            {{ form.docfile }}
        </p>
        <p><input type="submit" value="Upload" /></p>
    </form>

Answer 1

Answer for question 1:

If your upload file is less then FILE_UPLOAD_MAX_MEMORY_SIZE(2.5MB) , django puts the uploaded file in memory. If your file is bigger than 2.5MB, you can change FILE_UPLOAD_MAX_MEMORY_SIZE in your settings file