Django 将动态创建的文件保存到 s3

Question

我想为我的网站动态创建一个 css 文件，当我上传新的导航项目时该文件会更新。我知道我需要覆盖导航模型的保存，并且在文件上传到我的 s3 后，我可以调用一个函数来执行某些操作，但我不知道如何动态创建文件然后上传它到同一个 s3 服务器，但位置不同。

from django.db import models
from django.forms import CheckboxSelectMultiple

import tempfile

from django.conf import settings

from django.core.files.base import ContentFile
from django.core.files.storage import default_storage as s3_storage
from django.core.cache import cache

from datetime import datetime

import Image, os
import PIL.Image as PIL
import re, os, sys, urlparse

def createDynamicCSS():
    #create then save a css file here
    #probably best to 'navigation/nav.css'

    #loop through all entries and create class for all of them
    navs = PrimaryNav.all()

    cssfile = ""
    for n in navs:
        string = "." + n.slug + " { ... }"
        cssfile += string

    #save cssfile to s3



class PrimaryNav(models.Model):
    title = models.CharField(max_length=200)
    slug = models.SlugField(max_length=200)

    active = models.BooleanField()

   #saves to s3 (s3 address + /icon/ )
   icon = models.ImageField(upload_to='icons')

    def save(self):
        super(PrimaryNav, self).save() # Call the "real" save() method
        createDynamicCSS()

...

我不知道从哪里开始。我本来打算尝试剖析我在网上看到的 csv 函数，但事实证明这太困难了。请帮忙