def get_parent_list(self):
"""
Return all the ancestors of this model as a list ordered by MRO.
Useful for determining if something is an ancestor, regardless of lineage.
"""
result = OrderedSet(self.parents)
for parent in self.parents:
for ancestor in parent._meta.get_parent_list():
result.add(ancestor)
return list(result)
def process_rhs(self, compiler, connection):
db_rhs = getattr(self.rhs, '_db', None)
if db_rhs is not None and db_rhs != connection.alias:
raise ValueError(
"Subqueries aren't allowed across different databases. Force "
"the inner query to be evaluated using `list(inner_query)`.")
if self.rhs_is_direct_value():
try:
rhs = OrderedSet(self.rhs)
except TypeError: # Unhashable items in self.rhs
rhs = self.rhs
if not rhs:
raise EmptyResultSet
# rhs should be an iterable; use batch_process_rhs() to
# prepare/transform those values.
sqls, sqls_params = self.batch_process_rhs(compiler, connection,
rhs)
placeholder = '(' + ', '.join(sqls) + ')'
return (placeholder, sqls_params)
else:
if not getattr(self.rhs, 'has_select_fields', True):
self.rhs.clear_select_clause()
self.rhs.add_fields(['pk'])
return super().process_rhs(compiler, connection)
def iterative_dfs(self, start, forwards=True):
"""Iterative depth-first search for finding dependencies."""
visited = []
stack = [start]
while stack:
node = stack.pop()
visited.append(node)
stack += sorted(node.parents if forwards else node.children)
return list(OrderedSet(reversed(visited)))
def descendants(self):
# Use self.key instead of self to speed up the frequent hashing
# when constructing an OrderedSet.
if '_descendants' not in self.__dict__:
descendants = []
for child in sorted(self.children, reverse=True):
descendants += child.descendants()
descendants.append(self.key)
self.__dict__['_descendants'] = list(OrderedSet(descendants))
return self.__dict__['_descendants']
def ancestors(self):
# Use self.key instead of self to speed up the frequent hashing
# when constructing an OrderedSet.
if '_ancestors' not in self.__dict__:
ancestors = []
for parent in sorted(self.parents, reverse=True):
ancestors += parent.ancestors()
ancestors.append(self.key)
self.__dict__['_ancestors'] = list(OrderedSet(ancestors))
return self.__dict__['_ancestors']
def test_len(self):
s = OrderedSet()
self.assertEqual(len(s), 0)
s.add(1)
s.add(2)
s.add(2)
self.assertEqual(len(s), 2)
def python(self, options):
import code
# Set up a dictionary to serve as the environment for the shell, so
# that tab completion works on objects that are imported at runtime.
imported_objects = {}
try: # Try activating rlcompleter, because it's handy.
import readline
except ImportError:
pass
else:
# We don't have to wrap the following import in a 'try', because
# we already know 'readline' was imported successfully.
import rlcompleter
readline.set_completer(rlcompleter.Completer(imported_objects).complete)
# Enable tab completion on systems using libedit (e.g. macOS).
# These lines are copied from Python's Lib/site.py.
readline_doc = getattr(readline, '__doc__', '')
if readline_doc is not None and 'libedit' in readline_doc:
readline.parse_and_bind("bind ^I rl_complete")
else:
readline.parse_and_bind("tab:complete")
# We want to honor both $PYTHONSTARTUP and .pythonrc.py, so follow system
# conventions and get $PYTHONSTARTUP first then .pythonrc.py.
if not options['no_startup']:
for pythonrc in OrderedSet([os.environ.get("PYTHONSTARTUP"), os.path.expanduser('~/.pythonrc.py')]):
if not pythonrc:
continue
if not os.path.isfile(pythonrc):
continue
with open(pythonrc) as handle:
pythonrc_code = handle.read()
# Match the behavior of the cpython shell where an error in
# PYTHONSTARTUP prints an exception and continues.
try:
exec(compile(pythonrc_code, pythonrc, 'exec'), imported_objects)
except Exception:
traceback.print_exc()
code.interact(local=imported_objects)
def get_constraints(self, cursor, table_name):
"""
Retrieve any constraints or keys (unique, pk, fk, check, index) across
one or more columns.
"""
constraints = {}
# Get the actual constraint names and columns
name_query = """
SELECT kc.`constraint_name`, kc.`column_name`,
kc.`referenced_table_name`, kc.`referenced_column_name`
FROM information_schema.key_column_usage AS kc
WHERE
kc.table_schema = DATABASE() AND
kc.table_name = %s
ORDER BY kc.`ordinal_position`
"""
cursor.execute(name_query, [table_name])
for constraint, column, ref_table, ref_column in cursor.fetchall():
if constraint not in constraints:
constraints[constraint] = {
'columns': OrderedSet(),
'primary_key': False,
'unique': False,
'index': False,
'check': False,
'foreign_key':
(ref_table, ref_column) if ref_column else None,
}
constraints[constraint]['columns'].add(column)
# Now get the constraint types
type_query = """
SELECT c.constraint_name, c.constraint_type
FROM information_schema.table_constraints AS c
WHERE
c.table_schema = DATABASE() AND
c.table_name = %s
"""
cursor.execute(type_query, [table_name])
for constraint, kind in cursor.fetchall():
if kind.lower() == "primary key":
constraints[constraint]['primary_key'] = True
constraints[constraint]['unique'] = True
elif kind.lower() == "unique":
constraints[constraint]['unique'] = True
# Now add in the indexes
cursor.execute("SHOW INDEX FROM %s" %
self.connection.ops.quote_name(table_name))
for table, non_unique, index, colseq, column, type_ in [
x[:5] + (x[10], ) for x in cursor.fetchall()
]:
if index not in constraints:
constraints[index] = {
'columns': OrderedSet(),
'primary_key': False,
'unique': False,
'check': False,
'foreign_key': None,
}
constraints[index]['index'] = True
constraints[index][
'type'] = Index.suffix if type_ == 'BTREE' else type_.lower()
constraints[index]['columns'].add(column)
# Convert the sorted sets to lists
for constraint in constraints.values():
constraint['columns'] = list(constraint['columns'])
return constraints
def test_bool(self):
# Refs #23664
s = OrderedSet()
self.assertFalse(s)
s.add(1)
self.assertTrue(s)