How to change the file name of an uploaded file in Django?

Question

Is it possible to change the file name of an uploaded file in django? I searched, but couldn't find any answer.

My requirement is whenever a file is uploaded its file name should be changed in the following format.

format = userid + transaction_uuid + file_extension

Thank you very much...

Solution 1

How are you uploading the file? I assume with the FileField.

The documentation for FileField.upload_to says that the upload_to field,

may also be a callable, such as a function, which will be called to obtain the upload path, including the filename. This callable must be able to accept two arguments, and return a Unix-style path (with forward slashes) to be passed along to the storage system. The two arguments that will be passed are:

"instance": An instance of the model where the FileField is defined. More specifically, this is the particular instance where the current file is being attached.

"filename":The filename that was originally given to the file. This may or may not be taken into account when determining the final destination path.

So it looks like you just need to make a function to do your name handling and return the path.

def update_filename(instance, filename):
    path = "upload/path/"
    format = instance.userid + instance.transaction_uuid + instance.file_extension
    return os.path.join(path, format)

Solution 2

You need to have a FileField with the upload_to that calls to a callback, see [1]

Your callback should call a wrapper method which gets an instance as one of the params and filename as the other. [2]

Change it the way you like and return the new path [3]

1. LOGIC

FileField(..., upload_to=method_call(params),....)

2. define method

def method_call(params):
    return u'abc'

3. Wrapper:

def wrapper(instance, filename):
    return method

this is the rapper method that you need for getting the instance.

def wrapper(instance, filename):
... Your logic
...
return wrapper

Complete Code

def path_and_rename(path, prefix):
    def wrapper(instance, filename):
        ext = filename.split('.')[-1]
        project = "pid_%s" % (instance.project.id,)
        # get filename
        if instance.pk:
            complaint_id = "cid_%s" % (instance.pk,)
            filename = '{}.{}.{}.{}'.format(prefix, project, complaint_id, ext)
        else:
            # set filename as random string
            random_id = "rid_%s" % (uuid4().hex,)
            filename = '{}.{}.{}.{}'.format(prefix, project, random_id, ext)
            # return the whole path to the file
        return os.path.join(path, filename)

    return wrapper

Call to Method

sales_attach = models.FileField("Attachment", upload_to=path_and_rename("complaint_files", 'sales'), max_length=500,
                                help_text="Browse a file")

Hope this helps. Thanks.

Solution 3

if you want your function re-usable:

import hashlib
import datetime
import os
from functools import partial

def _update_filename(instance, filename, path):
    path = path

    filename = "..."

    return os.path.join(path, filename)

def upload_to(path):
    return partial(_update_filename, path=path)

You just have to use it this way:

document = models.FileField(upload_to=upload_to("my/path"))

Solution 4

import random
import os
def generate_unique_name(path):
    def wrapper(instance, filename):
        extension = "." + filename.split('.')[-1]
        filename = str(random.randint(10,99)) + str(random.randint(10,99)) + str(random.randint(10,99)) + str(random.randint(10,99))  + extension
        return os.path.join(path, filename)
    return wrapper

#You just have to use it this way:#

 photo = models.FileField("Attachment", upload_to=generate_unique_name("pics"),max_length=500,help_text="Browse a photo")

Solution 5

Incase this may help anyone.

import os
import uuid
import random

from datetime import datetime 

def user_directory_path(instance, filename):
    # Get Current Date
    todays_date = datetime.now()

    path = "uploads/{}/{}/{}/".format(todays_date.year, todays_date.month, todays_date.day)
    extension = "." + filename.split('.')[-1]
    stringId = str(uuid.uuid4())
    randInt = str(random.randint(10, 99))

    # Filename reformat
    filename_reformat = stringId + randInt + extension

    return os.path.join(path, filename_reformat)


class MyModel(models.Model):
    upload = models.FileField(upload_to=user_directory_path)

View more solutions

Comments

[John Mee]

excepting if the file exists; does the storage butcher your creation to get a unique name?

[Seb Ashton]

For others coming to the answer (like me) please note that the path cannot start with a / otherwise django will through an error due to a "Suspicious Operation" so you use @monkut 's example path = "/upload/path/" should be path = "upload/path/"

[Olivier Pons]

be careful that if you create your custom validation function in a form like def clean_my_audio_file_field(self): then the result of this function will override whatever you do in the upload_to= parameter

[Renel Chesak]

What if you want the file name to include the value from a drop down menu? How can you make that value available to models.py?

[Cyley Simon]

@SoftwareEnthusiastic Can you let me know this function def update_file_name() where this was written in views.py?

[Jorge Arévalo]

What if you need instance.id to generate the filename?

[user2471801]

include it in the returned string, return f'{instance.id}/{filename}'

[The EasyLearn Academy]

I got error in project and uuid. so i have created my own function given as another answer

[Haykins]

or the path can be path="uploads/" for a single directory

[Khaled]

Please Insert the code part as a code format and not as a text format