Commit 829dc3c5 authored by Marc Tamlyn's avatar Marc Tamlyn Committed by Claude Paroz
Browse files

Fixed #20094 - Be more careful when checking for Iterator 

Python 2.6 has some different behaviour when checking
isinstance(foo, collections.Iterator).
parent f7795e96

django/db/models/fields/__init__.py

+2 −2
Original line number Diff line number Diff line 
from __future__ import unicode_literals



import collections

import copy

import datetime

import decimal
@@ -18,6 +17,7 @@ from django.core import exceptions, validators 
from django.utils.datastructures import DictWrapper

from django.utils.dateparse import parse_date, parse_datetime, parse_time

from django.utils.functional import curry, total_ordering

from django.utils.itercompat import is_iterator

from django.utils.text import capfirst

from django.utils import timezone

from django.utils.translation import ugettext_lazy as _
@@ -488,7 +488,7 @@ class Field(object): 
        return bound_field_class(self, fieldmapping, original)



    def _get_choices(self):

        if isinstance(self._choices, collections.Iterator):

        if is_iterator(self._choices):

            choices, self._choices = tee(self._choices)

            return choices

        else:

django/db/models/sql/where.py

+2 −2
Original line number Diff line number Diff line
@@ -4,7 +4,6 @@ Code to manage the creation and SQL rendering of 'where' constraints. 


from __future__ import absolute_import



import collections

import datetime

from itertools import repeat
@@ -12,6 +11,7 @@ from django.conf import settings 
from django.db.models.fields import DateTimeField, Field

from django.db.models.sql.datastructures import EmptyResultSet, Empty

from django.db.models.sql.aggregates import Aggregate

from django.utils.itercompat import is_iterator

from django.utils.six.moves import xrange

from django.utils import timezone

from django.utils import tree
@@ -58,7 +58,7 @@ class WhereNode(tree.Node): 
        if not isinstance(data, (list, tuple)):

            return data

        obj, lookup_type, value = data

        if isinstance(value, collections.Iterator):

        if is_iterator(value):

            # Consume any generators immediately, so that we can determine

            # emptiness and transform any non-empty values correctly.

            value = list(value)

django/utils/itercompat.py

+14 −1
Original line number Diff line number Diff line
@@ -4,10 +4,12 @@ Where possible, we try to use the system-native version and only fall back to 
these implementations if necessary.

"""



from django.utils.six.moves import builtins

import collections

import itertools

import sys

import warnings





def is_iterable(x):

    "A implementation independent way of checking for iterables"

    try:
@@ -17,6 +19,17 @@ def is_iterable(x): 
    else:

        return True



def is_iterator(x):

    """An implementation independent way of checking for iterators



    Python 2.6 has a different implementation of collections.Iterator which

    accepts anything with a `next` method. 2.7+ requires and `__iter__` method

    as well.

    """

    if sys.version_info >= (2, 7):

        return isinstance(x, collections.Iterator)

    return isinstance(x, collections.Iterator) and hasattr(x, '__iter__')



def product(*args, **kwds):

    warnings.warn("django.utils.itercompat.product is deprecated; use the native version instead",

                  DeprecationWarning, stacklevel=2)

tests/utils_tests/itercompat.py

0 → 100644
+11 −0
Original line number Diff line number Diff line 
from django.test import TestCase



from .models import Category, Thing





class TestIsIterator(TestCase):

    def test_regression(self):

        """This failed on Django 1.5/Py2.6 because category has a next method."""

        category = Category.objects.create(name='category')

        Thing.objects.create(category=category)

        Thing.objects.filter(category=category)

tests/utils_tests/models.py

+13 −1
Original line number Diff line number Diff line 
# Test runner needs a models.py file.
 
from django.db import models





class Category(models.Model):

    name = models.CharField(max_length=100)



    def next(self):

        return self





class Thing(models.Model):

    name = models.CharField(max_length=100)

    category = models.ForeignKey(Category)