Python Django 不会用旧文件覆盖新上传的文件答案

【问题标题】：Python Django does not overwrite newly uploaded file with old onePython Django 不会用旧文件覆盖新上传的文件
【发布时间】：2018-06-28 05:40:10
【问题描述】：

我想在上传新文件时覆盖/替换文件。目前，该应用程序可以将文件上传到特定文件夹，但在上传新文件的情况下不会覆盖文件。我需要帮助来解决这个问题。

views.py

def uploadfunc(request):
    if request.method=='POST':
        form =uploadfileform(request.POST,request.FILES)
        if form.is_valid():
            form.save()
            return render_to_response('upload_successful.html')
    else:
        form=uploadfileform()
    return render(request, 'upload.html',{'form':form})

models.py

class uploadfolder(models.Model):
    """ my application """
    File_to_upload = models.FileField(upload_to='')

forms.py

class uploadfileform(forms.ModelForm):
    class Meta:
        model=uploadfolder
        fields=('File_to_upload',)

【问题讨论】：

您的项目中是否只需要上传一个文件？
ImageField overwrite image file with same name的可能重复
请阅读django codestyle

标签： python django django-views

【解决方案1】：

您可以使用 Django pre_save 信号来实现这一点，如果存在，它将在保存之前删除文件。

from django.db.models.signals import pre_save
from django.dispatch import receiver
import os

#It will activate whenever you will save file in uploadfolder model
@receiver(pre_save, sender=uploadfolder)
def file_update(sender, **kwargs):
    upload_folder_instance = kwargs['instance']
    if upload_folder_instance.id:
        path = upload_folder_instance.file_to_upload.path
        os.remove(path)

希望它会有所帮助。

【讨论】：

【解决方案2】：

感谢 @vermanil 我更新 models.py 对我有用。

from django.db.models.signals import pre_save
from django.dispatch import receiver
import os

class uploadfolder(models.Model):
    """ my application """
    File_to_upload = models.FileField(upload_to='')

@receiver(pre_save, sender=uploadfolder)
def file_update(sender, **kwargs):
    upload_folder_instance = kwargs['instance']
    if upload_folder_instance.File_to_upload:
        path = upload_folder_instance.File_to_upload.path
        os.remove(path)

【讨论】：