Mengelola berkas¶

Menggunakan berkas dalam model¶

Ketika anda menggunakan FileField atau ImageField, Django menyediakan sekumpulan dari API anda dapat gunakan untuk berhbungan dengan berkas itu.

Pertimbangkan model berikut, menggunakan ImageField untuk menyimpan sebuah foto:

from django.db import models


class Car(models.Model):
    name = models.CharField(max_length=255)
    price = models.DecimalField(max_digits=5, decimal_places=2)
    photo = models.ImageField(upload_to="cars")
    specs = models.FileField(upload_to="specs")

Any Car instance will have a photo attribute that you can use to get at the details of the attached photo:

>>> car = Car.objects.get(name="57 Chevy")
>>> car.photo
<ImageFieldFile: cars/chevy.jpg>
>>> car.photo.name
'cars/chevy.jpg'
>>> car.photo.path
'/media/cars/chevy.jpg'
>>> car.photo.url
'http://media.example.com/cars/chevy.jpg'

Obyek ini -- car.photo dalam contoh -- adalah obyek File, yang berarti itu mempunyai semua metode-metode dan atribut-atribut digambarkan dibawah.

For example, you can change the file name by setting the file's name to a path relative to the file storage's location (MEDIA_ROOT if you are using the default FileSystemStorage):

>>> import os
>>> from django.conf import settings
>>> initial_path = car.photo.path
>>> car.photo.name = "cars/chevy_ii.jpg"
>>> new_path = settings.MEDIA_ROOT + car.photo.name
>>> # Move the file on the filesystem
>>> os.rename(initial_path, new_path)
>>> car.save()
>>> car.photo.path
'/media/cars/chevy_ii.jpg'
>>> car.photo.path == new_path
True

To save an existing file on disk to a FileField:

>>> from pathlib import Path
>>> from django.core.files import File
>>> path = Path("/some/external/specs.pdf")
>>> car = Car.objects.get(name="57 Chevy")
>>> with path.open(mode="rb") as f:
...     car.specs = File(f, name=path.name)
...     car.save()
...

>>> from PIL import Image
>>> car = Car.objects.get(name="57 Chevy")
>>> car.photo.width
191
>>> car.photo.height
287
>>> image = Image.open(car.photo)
# Raises ValueError: seek of closed file.
>>> car.photo.open()
<ImageFieldFile: cars/chevy.jpg>
>>> image = Image.open(car.photo)
>>> image
<PIL.JpegImagePlugin.JpegImageFile image mode=RGB size=191x287 at 0x7F99A94E9048>

Obyek File¶

Di bagian dalam, Django menggunakan sebuah instance django.core.files.File kapanpun itu butuh untuk mewakili sebuah berkas.

Most of the time you'll use a File that Django's given you (i.e. a file attached to a model as above, or perhaps an uploaded file).

If you need to construct a File yourself, the easiest way is to create one using a Python built-in file object:

>>> from django.core.files import File

# Create a Python file object using open()
>>> f = open("/path/to/hello.world", "w")
>>> myfile = File(f)

Sekarang anda dapat menggunakan atribut-atribut terdokumentasi apapun dan metode-metode dari kelas File.

Be aware that files created in this way are not automatically closed. The following approach may be used to close files automatically:

>>> from django.core.files import File

# Create a Python file object using open() and the with statement
>>> with open("/path/to/hello.world", "w") as f:
...     myfile = File(f)
...     myfile.write("Hello World")
...
>>> myfile.closed
True
>>> f.closed
True

Closing files is especially important when accessing file fields in a loop over a large number of objects. If files are not manually closed after accessing them, the risk of running out of file descriptors may arise. This may lead to the following error:

OSError: [Errno 24] Too many open files

Penyimpanan berkas¶

Behind the scenes, Django delegates decisions about how and where to store files to a file storage system. This is the object that actually understands things like file systems, opening and reading files, etc.

Django's default file storage is 'django.core.files.storage.FileSystemStorage'. If you don't explicitly provide a storage system in the default key of the STORAGES setting, this is the one that will be used.

Lihat dibawah untuk rincian dari sistem penyimpanan berkas awalan siap-pakai, dan lihat Bagaimana menulis kelas penyimpanan disesuaikan untuk informasi pada menulis sistem penyimpanan berkas anda sendiri.

>>> from django.core.files.base import ContentFile
>>> from django.core.files.storage import default_storage

>>> path = default_storage.save("path/to/file", ContentFile(b"new content"))
>>> path
'path/to/file'

>>> default_storage.size(path)
11
>>> default_storage.open(path).read()
b'new content'

>>> default_storage.delete(path)
>>> default_storage.exists(path)
False

from django.core.files.storage import FileSystemStorage
from django.db import models

fs = FileSystemStorage(location="/media/photos")


class Car(models.Model):
    ...
    photo = models.ImageField(storage=fs)

from django.conf import settings
from django.db import models
from .storages import MyLocalStorage, MyRemoteStorage


def select_storage():
    return MyLocalStorage() if settings.DEBUG else MyRemoteStorage()


class MyModel(models.Model):
    my_file = models.FileField(storage=select_storage)

from django.core.files.storage import storages


def select_storage():
    return storages["mystorage"]


class MyModel(models.Model):
    upload = models.FileField(storage=select_storage)