Django图片上传触发MultiValueDictKeyError错误，求解决方案

问题场景 #

使用Django实现图片上传功能，已编写views.py、HTML模板及ProfileForm表单类，但上传图片时触发MultiValueDictKeyError，错误提示键'image'不存在。

相关代码 #

views.py

# Create your views here.
def store_file(file):
    with open("temp/mensschappy.png", "wb+") as dest:
        for chunk in file.chunks():
            dest.write(chunk)


class CreateProfileView(View):
    def get(self, request):
        form = ProfileForm()
        return render(request, "profiles/create_profile.html", {
            "form": form
        })

    def post(self, request):
        submitted_form = ProfileForm(request.POST, request.FILES)

        if submitted_form.is_valid():
            store_file(request.FILES["image"])
            return HttpResponseRedirect("/profiles")

        return render(request, "profiles/create_profile.html", {
            "form": submitted_form
        })

HTML模板

{% load static %}
<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Create a Profile</title>
    <link rel="stylesheet" href="{% static "profiles/styles.css" %}">
  </head>
  <body>
    <form action="/profiles/" method="post" enctype="multipart/form-data">
      {% csrf_token %} {{ form }}

      <button>Upload!</button>
    </form>   
  </body>
</html>

ProfileForm

from django import forms

class ProfileForm(forms.Form):
    upload_file = forms.FileField()

错误信息 #

MultiValueDictKeyError at /profiles/

'image'

Request Method:     POST
Request URL:    http://127.0.0.1:8000/profiles/
Django Version:     4.1.1
Exception Type:     MultiValueDictKeyError
Exception Value:

'image'

Exception Location:     C:\Python310\lib\site-packages\django\utils\datastructures.py, line 86, in __getitem__
Raised during:  profiles.views.CreateProfileView
Python Executable:  C:\Python310\python.exe
Python Version:     3.10.6
Python Path:

['C:\Users\engel\Documents\NVWA\software\blockchainfruit\schoolfruitnvwa',
 'C:\Python310\python310.zip',
 'C:\Python310\DLLs',
 'C:\Python310\lib',
 'C:\Python310',
 'C:\Python310\lib\site-packages']

Server time:    Thu, 06 Oct 2022 08:38:50 +0000

问题原因 #

表单类ProfileForm中定义的文件字段名为upload_file，但视图CreateProfileView的post方法中，尝试从request.FILES中获取键为image的文件，两者名称不匹配，导致找不到对应键，触发MultiValueDictKeyError。

解决方法 #

只需保证表单字段名与视图中调用的键名一致，有两种方案可选：

方案一：修改视图中的键名，匹配表单字段 #

将views.py中store_file(request.FILES["image"])改为：

store_file(request.FILES["upload_file"])

方案二：修改表单字段名，匹配视图中的键 #

将ProfileForm中的字段名改为image：

from django import forms

class ProfileForm(forms.Form):
    image = forms.FileField()

更规范的写法：使用表单清理后的数据 #

推荐通过表单的cleaned_data获取上传文件，无需直接操作request.FILES，代码更健壮且易于维护：

if submitted_form.is_valid():
    store_file(submitted_form.cleaned_data["upload_file"])  # 或对应修改后的字段名image
    return HttpResponseRedirect("/profiles")

内容的提问来源于stack exchange，提问作者mightycode Newton