entityMap|blocks|key|3i2pn|text|@Anton+Strogonoff|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3qqg4|我在代码中遗漏了一些东西，当一个文件改变时，如果你创建一个新文件生成一个错误，因为是一个新文件没有找到一个路径。我修改了函数的代码，并添加了try/except语句，它工作得很好。|d465o|@receiver(models.signals.pre_save,+sender=MediaFile)
def+auto_delete_file_on_change(sender,+instance,+**kwargs):
++++"""Deletes+file+from+filesystem
++++when+corresponding+`MediaFile`+object+is+changed.
++++"""
++++if+not+instance.pk:
++++++++return+False

++++try:
++++++++old_file+=+MediaFile.objects.get(pk=instance.pk).file
++++except+MediaFile.DoesNotExist:
++++++++return+False

++++new_file+=+instance.file
++++if+not+old_file+==+new_file:
++++++++try:
++++++++++++if+os.path.isfile(old_file.path):
++++++++++++++++os.remove(old_file.path)
++++++++except+Exception:
++++++++++++return+False|code-block|syntax|javascript^0|0|0^^$0|$]|1|@$2|3|4|5|6|7|8|J|9|@]|A|@]|B|$]]|$2|C|4|D|6|7|8|K|9|@]|A|@]|B|$]]|$2|E|4|F|6|G|8|L|9|@]|A|@]|B|$H|I]]]]

@Anton Strogonoff

I missing something in the code when a file change, if you create a new file generate an error, becuase is a new file a did not find a path. I modified the code of function and added a try/except sentence and it works well. 

<pre><code>@receiver(models.signals.pre_save, sender=MediaFile)
def auto_delete_file_on_change(sender, instance, **kwargs):
 """Deletes file from filesystem
 when corresponding `MediaFile` object is changed.
 """
 if not instance.pk:
 return False

 try:
 old_file = MediaFile.objects.get(pk=instance.pk).file
 except MediaFile.DoesNotExist:
 return False

 new_file = instance.file
 if not old_file == new_file:
 try:
 if os.path.isfile(old_file.path):
 os.remove(old_file.path)
 except Exception:
 return False
</code></pre>

entityMap|blocks|key|4id17|text|这是一个应用程序，只要模型被删除或新文件被上传，它就会删除旧文件：django-smartfields|type|unstyled|depth|inlineStyleRanges|entityRanges|data|bens3|from+django.db+import+models
from+smartfields+import+fields

class+Song(models.Model):
++++song+=+fields.FileField(upload_to='/songs/')
++++image+=+fields.ImageField(upload_to='/pictures/',+blank=True)|code-block|syntax|javascript^0|0^^$0|$]|1|@$2|3|4|5|6|7|8|H|9|@]|A|@]|B|$]]|$2|C|4|D|6|E|8|I|9|@]|A|@]|B|$F|G]]]]

Here is an app that will remove old files whenever model is deleted or a new file is uploaded: <a href="https://github.com/lehins/django-smartfields" rel="noreferrer">django-smartfields</a>

<pre><code>from django.db import models
from smartfields import fields

class Song(models.Model):
 song = fields.FileField(upload_to='/songs/')
 image = fields.ImageField(upload_to='/pictures/', blank=True)
</code></pre>

entityMap|blocks|key|a87km|text|您还可以简单地覆盖模型的delete函数，以检查文件是否存在，并在调用超级函数之前将其删除。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|55ir4|import+os

class+Excel(models.Model):
++++upload_file+=+models.FileField(upload_to='/excels/',+blank+=True)+++
++++uploaded_on+=+models.DateTimeField(editable=False)


++++def+delete(self,*args,**kwargs):
++++++++if+os.path.isfile(self.upload_file.path):
++++++++++++os.remove(self.upload_file.path)

++++++++super(Excel,+self).delete(*args,**kwargs)|code-block|syntax|javascript^0|0^^$0|$]|1|@$2|3|4|5|6|7|8|H|9|@]|A|@]|B|$]]|$2|C|4|D|6|E|8|I|9|@]|A|@]|B|$F|G]]]]

You can also simply overwrite the delete function of the model to check for file if it exists and delete it before calling the super function.

<pre><code>import os

class Excel(models.Model):
 upload_file = models.FileField(upload_to='/excels/', blank =True) 
 uploaded_on = models.DateTimeField(editable=False)


 def delete(self,*args,**kwargs):
 if os.path.isfile(self.upload_file.path):
 os.remove(self.upload_file.path)

 super(Excel, self).delete(*args,**kwargs)
</code></pre>

entityMap|blocks|key|7cg42|text|尝试django-清理，当您移除模型时，它会自动调用FileField上的delete方法。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|futqd|pip+install+django-cleanup|code-block|syntax|javascript|dbede|settings.py|buhm8|INSTALLED_APPS+=+(
+++++...
++++'django_cleanup',+#+should+go+after+your+apps
)^0|0|0|0^^$0|$]|1|@$2|3|4|5|6|7|8|L|9|@]|A|@]|B|$]]|$2|C|4|D|6|E|8|M|9|@]|A|@]|B|$F|G]]|$2|H|4|I|6|7|8|N|9|@]|A|@]|B|$]]|$2|J|4|K|6|E|8|O|9|@]|A|@]|B|$F|G]]]]

Try <a href="https://github.com/un1t/django-cleanup" rel="nofollow noreferrer">django-cleanup</a>, it automatically invokes delete method on FileField when you remove model.
<pre><code>pip install django-cleanup
</code></pre>
settings.py
<pre><code>INSTALLED_APPS = (
 ...
 'django_cleanup.apps.CleanupConfig',
)
</code></pre>

entityMap|blocks|key|bvtbh|text|您可以通过调用以下命令从文件系统中删除文件.delete++Django+>=+1.10文件字段的方法如下图所示：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|amk1b|obj+=+Song.objects.get(pk=1)
obj.song.delete()|code-block|syntax|javascript^0|0^^$0|$]|1|@$2|3|4|5|6|7|8|H|9|@]|A|@]|B|$]]|$2|C|4|D|6|E|8|I|9|@]|A|@]|B|$F|G]]]]

You can delete file from filesystem with calling <code>.delete</code> method of file field shown as below with Django >= 1.10:

<pre><code>obj = Song.objects.get(pk=1)
obj.song.delete()
</code></pre>

entityMap|blocks|key|13oer|text|这段代码将在我每次上传新图像(徽标字段)并检查徽标是否已经存在时运行，如果存在，则关闭它并将其从磁盘中删除。当然，在接收器函数中也可以进行相同的过程。希望这能有所帮助。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|5itdc|#++Returns+the+file+path+with+a+folder+named+by+the+company+under+/media/uploads
++++def+logo_file_path(instance,+filename):
++++++++company_instance+=+Company.objects.get(pk=instance.pk)
++++++++if+company_instance.logo:
++++++++++++logo+=+company_instance.logo
++++++++++++if+logo.file:
++++++++++++++++if+os.path.isfile(logo.path):
++++++++++++++++++++logo.file.close()
++++++++++++++++++++os.remove(logo.path)

++++++++return+'uploads/{0}/{1}'.format(instance.name.lower(),+filename)


++++class+Company(models.Model):
++++++++name+=+models.CharField(_("Company"),+null=False,+blank=False,+unique=True,+max_length=100)+
++++++++logo+=+models.ImageField(upload_to=logo_file_path,+default='')|code-block|syntax|javascript^0|0^^$0|$]|1|@$2|3|4|5|6|7|8|H|9|@]|A|@]|B|$]]|$2|C|4|D|6|E|8|I|9|@]|A|@]|B|$F|G]]]]

This code will run every time i upload a new image (logo field) and check if a logo already exists if so, close it and remove it from disk. The same procedure could of course be made in receiver function. Hope this helps.

<pre><code> # Returns the file path with a folder named by the company under /media/uploads
 def logo_file_path(instance, filename):
 company_instance = Company.objects.get(pk=instance.pk)
 if company_instance.logo:
 logo = company_instance.logo
 if logo.file:
 if os.path.isfile(logo.path):
 logo.file.close()
 os.remove(logo.path)

 return 'uploads/{0}/{1}'.format(instance.name.lower(), filename)


 class Company(models.Model):
 name = models.CharField(_("Company"), null=False, blank=False, unique=True, max_length=100) 
 logo = models.ImageField(upload_to=logo_file_path, default='')
</code></pre>

entityMap|blocks|key|9oq7c|text|对于那些在较新版本的Django+(目前是3.1)中寻找答案的人。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|feakl|我发现了这个网站它在我没有任何改变的情况下工作，只需将它添加到您的models.py:|offset|length|style|CODE|4q76l|from+django.db.models.signals+import+post_delete
from+django.dispatch+import+receiver
from+django.db+import+models
+
"""+Only+delete+the+file+if+no+other+instances+of+that+model+are+using+it"""++++
def+delete_file_if_unused(model,instance,field,instance_file_field):
++++dynamic_field+=+{}
++++dynamic_field[field.name]+=+instance_file_field.name
++++other_refs_exist+=+model.objects.filter(**dynamic_field).exclude(pk=instance.pk).exists()
++++if+not+other_refs_exist:
++++++++instance_file_field.delete(False)
"""+Whenever+ANY+model+is+deleted,+if+it+has+a+file+field+on+it,+delete+the+associated+file+too"""
@receiver(post_delete)
def+delete_files_when_row_deleted_from_db(sender,+instance,+**kwargs):
++++for+field+in+sender._meta.concrete_fields:
++++++++if+isinstance(field,models.FileField):
++++++++++++instance_file_field+=+getattr(instance,field.name)
++++++++++++delete_file_if_unused(sender,instance,field,instance_file_field)
++++++++++++
"""+Delete+the+file+if+something+else+get+uploaded+in+its+place"""
@receiver(pre_save)
def+delete_files_when_file_changed(sender,instance,+**kwargs):
++++#+Don't+run+on+initial+save
++++if+not+instance.pk:
++++++++return
++++for+field+in+sender._meta.concrete_fields:
++++++++if+isinstance(field,models.FileField):
++++++++++++#its+got+a+file+field.+Let's+see+if+it+changed
++++++++++++try:
++++++++++++++++instance_in_db+=+sender.objects.get(pk=instance.pk)
++++++++++++except+sender.DoesNotExist:
++++++++++++++++#+We+are+probably+in+a+transaction+and+the+PK+is+just+temporary
++++++++++++++++#+Don't+worry+about+deleting+attachments+if+they+aren't+actually+saved+yet.
++++++++++++++++return
++++++++++++instance_in_db_file_field+=+getattr(instance_in_db,field.name)
++++++++++++instance_file_field+=+getattr(instance,field.name)
++++++++++++if+instance_in_db_file_field.name+!=+instance_file_field.name:
++++++++++++++++delete_file_if_unused(sender,instance,field,instance_in_db_file_field)|code-block|syntax|javascript^0|0|X|9|0^^$0|$]|1|@$2|3|4|5|6|7|8|N|9|@]|A|@]|B|$]]|$2|C|4|D|6|7|8|O|9|@$E|P|F|Q|G|H]]|A|@]|B|$]]|$2|I|4|J|6|K|8|R|9|@]|A|@]|B|$L|M]]]]

For those who look for an answer in a newer version of Django (currently 3.1).
I found this <a href="https://cmljnelson.blog/2020/06/22/delete-files-when-deleting-models-in-django/" rel="nofollow noreferrer">website</a> and it worked for me without any changes, just add it in your <code>models.py</code>:
<pre><code>from django.db.models.signals import post_delete
from django.dispatch import receiver
from django.db import models
 
&quot;&quot;&quot; Only delete the file if no other instances of that model are using it&quot;&quot;&quot; 
def delete_file_if_unused(model,instance,field,instance_file_field):
 dynamic_field = {}
 dynamic_field[field.name] = instance_file_field.name
 other_refs_exist = model.objects.filter(**dynamic_field).exclude(pk=instance.pk).exists()
 if not other_refs_exist:
 instance_file_field.delete(False)
&quot;&quot;&quot; Whenever ANY model is deleted, if it has a file field on it, delete the associated file too&quot;&quot;&quot;
@receiver(post_delete)
def delete_files_when_row_deleted_from_db(sender, instance, **kwargs):
 for field in sender._meta.concrete_fields:
 if isinstance(field,models.FileField):
 instance_file_field = getattr(instance,field.name)
 delete_file_if_unused(sender,instance,field,instance_file_field)
 
&quot;&quot;&quot; Delete the file if something else get uploaded in its place&quot;&quot;&quot;
@receiver(pre_save)
def delete_files_when_file_changed(sender,instance, **kwargs):
 # Don't run on initial save
 if not instance.pk:
 return
 for field in sender._meta.concrete_fields:
 if isinstance(field,models.FileField):
 #its got a file field. Let's see if it changed
 try:
 instance_in_db = sender.objects.get(pk=instance.pk)
 except sender.DoesNotExist:
 # We are probably in a transaction and the PK is just temporary
 # Don't worry about deleting attachments if they aren't actually saved yet.
 return
 instance_in_db_file_field = getattr(instance_in_db,field.name)
 instance_file_field = getattr(instance,field.name)
 if instance_in_db_file_field.name != instance_file_field.name:
 delete_file_if_unused(sender,instance,field,instance_in_db_file_field)
</code></pre>

I'm building a web app in Django. I have a model that uploads a file, but I can not delete the file. Here is my code:
<pre><code>class Song(models.Model):
 name = models.CharField(blank=True, max_length=100)
 author = models.ForeignKey(User, to_field='id', related_name=&quot;id_user2&quot;)
 song = models.FileField(upload_to='/songs/')
 image = models.ImageField(upload_to='/pictures/', blank=True)
 date_upload = models.DateField(auto_now_add=True)

 def delete(self, *args, **kwargs):
 # You have to prepare what you need before delete the model
 storage, path = self.song.storage, self.song.path
 # Delete the model before the file
 super(Song, self).delete(*args, **kwargs)
 # Delete the file after the model
 storage.delete(path)
</code></pre>
Then, in <code>python manage.py shell</code> I do this:
<pre><code>song = Song.objects.get(pk=1)
song.delete()
</code></pre>
It deletes the record from the database but not the file on server.
What else can I try?
Thanks!

Django delete FileField

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 我正在用Django构建一个web应用程序。我有一个上传文件的模型，但我不能删除该文件。下面是我的代码： class Song(models.Model):    name = models.CharField(blank=True, max_length=100)    author = models.Foreig...

问Django删除FileField
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