diff options
Diffstat (limited to 'docs/ref/models')
| -rw-r--r-- | docs/ref/models/instances.txt | 26 | ||||
| -rw-r--r-- | docs/ref/models/querysets.txt | 11 |
2 files changed, 28 insertions, 9 deletions
diff --git a/docs/ref/models/instances.txt b/docs/ref/models/instances.txt index 2177bc6a59..2371fd3c8a 100644 --- a/docs/ref/models/instances.txt +++ b/docs/ref/models/instances.txt @@ -463,9 +463,29 @@ the conversion to string objects when required. .. method:: Model.__str__() -The ``__str__()`` method is called whenever you call ``str()`` on an object. The main use for this method directly inside Django is when the ``repr()`` output of a model is displayed anywhere (for example, in debugging output). -Thus, you should return a nice, human-readable string for the object's -``__str__()``. It isn't required to put ``__str__()`` methods everywhere if you have sensible :meth:`~Model.__unicode__()` methods. +The ``__str__()`` method is called whenever you call ``str()`` on an +object. In Python 3, Django uses ``str(obj)`` in a number of +places. Most notably, to display an object in the Django admin site +and as the value inserted into a template when it displays an +object. Thus, you should always return a nice, human-readable +representation of the model from the ``__str__()`` method. + +For example:: + + from django.db import models + + class Person(models.Model): + first_name = models.CharField(max_length=50) + last_name = models.CharField(max_length=50) + + def __str__(self): + return '%s %s' % (self.first_name, self.last_name) + +In Python 2, the main use of ``__str__`` directly inside Django is +when the ``repr()`` output of a model is displayed anywhere (for +example, in debugging output). It isn't required to put ``__str__()`` +methods everywhere if you have sensible :meth:`~Model.__unicode__()` +methods. The previous :meth:`~Model.__unicode__()` example could be similarly written using ``__str__()`` like this:: diff --git a/docs/ref/models/querysets.txt b/docs/ref/models/querysets.txt index c063d38aa6..94f9c6b36b 100644 --- a/docs/ref/models/querysets.txt +++ b/docs/ref/models/querysets.txt @@ -812,17 +812,16 @@ For example, suppose you have these models:: name = models.CharField(max_length=50) toppings = models.ManyToManyField(Topping) - # On Python 3: def __str__(self): - def __unicode__(self): - return u"%s (%s)" % (self.name, u", ".join([topping.name - for topping in self.toppings.all()])) + def __str__(self): # __unicode__ on Python 2 + return "%s (%s)" % (self.name, ", ".join([topping.name + for topping in self.toppings.all()])) and run:: >>> Pizza.objects.all() - [u"Hawaiian (ham, pineapple)", u"Seafood (prawns, smoked salmon)"... + ["Hawaiian (ham, pineapple)", "Seafood (prawns, smoked salmon)"... -The problem with this is that every time ``Pizza.__unicode__()`` asks for +The problem with this is that every time ``Pizza.__str__()`` asks for ``self.toppings.all()`` it has to query the database, so ``Pizza.objects.all()`` will run a query on the Toppings table for **every** item in the Pizza ``QuerySet``. |