Run black -l 79 against all source files

This is a straight reformat run using black as is, with no edits
applied at all.

The black run will format code consistently, however in
some cases that are prevalent in SQLAlchemy code it produces
too-long lines.   The too-long lines will be resolved in the
following commit that will resolve all remaining flake8 issues
including shadowed builtins, long lines, import order, unused
imports, duplicate imports, and docstring issues.

Change-Id: I7eda77fed3d8e73df84b3651fd6cfcfe858d4dc9

4 files changed, 225 insertions, 106 deletions

diff --git a/examples/elementtree/__init__.py b/examples/elementtree/__init__.py
index 66e9cfbbe..82d00ff5a 100644
--- a/examples/elementtree/__init__.py
+++ b/examples/elementtree/__init__.py
@@ -22,4 +22,4 @@ E.g.::
 .. autosource::
     :files: pickle.py, adjacency_list.py, optimized_al.py
 
-"""
\ No newline at end of file
+"""
diff --git a/examples/elementtree/adjacency_list.py b/examples/elementtree/adjacency_list.py
index 5e27ba9ca..1f7161212 100644
--- a/examples/elementtree/adjacency_list.py
+++ b/examples/elementtree/adjacency_list.py
@@ -15,42 +15,63 @@ styles of persistence are identical, as is the structure of the main Document cl
 """
 
 ################################# PART I - Imports/Coniguration ####################################
-from sqlalchemy import (MetaData, Table, Column, Integer, String, ForeignKey,
-    Unicode, and_, create_engine)
+from sqlalchemy import (
+    MetaData,
+    Table,
+    Column,
+    Integer,
+    String,
+    ForeignKey,
+    Unicode,
+    and_,
+    create_engine,
+)
 from sqlalchemy.orm import mapper, relationship, Session, lazyload
 
 import sys, os, io, re
 
 from xml.etree import ElementTree
 
-e = create_engine('sqlite://')
+e = create_engine("sqlite://")
 meta = MetaData()
 
 ################################# PART II - Table Metadata #########################################
 
 # stores a top level record of an XML document.
-documents = Table('documents', meta,
-    Column('document_id', Integer, primary_key=True),
-    Column('filename', String(30), unique=True),
-    Column('element_id', Integer, ForeignKey('elements.element_id'))
+documents = Table(
+    "documents",
+    meta,
+    Column("document_id", Integer, primary_key=True),
+    Column("filename", String(30), unique=True),
+    Column("element_id", Integer, ForeignKey("elements.element_id")),
 )
 
 # stores XML nodes in an adjacency list model.  This corresponds to
 # Element and SubElement objects.
-elements = Table('elements', meta,
-    Column('element_id', Integer, primary_key=True),
-    Column('parent_id', Integer, ForeignKey('elements.element_id')),
-    Column('tag', Unicode(30), nullable=False),
-    Column('text', Unicode),
-    Column('tail', Unicode)
-    )
+elements = Table(
+    "elements",
+    meta,
+    Column("element_id", Integer, primary_key=True),
+    Column("parent_id", Integer, ForeignKey("elements.element_id")),
+    Column("tag", Unicode(30), nullable=False),
+    Column("text", Unicode),
+    Column("tail", Unicode),
+)
 
 # stores attributes.  This corresponds to the dictionary of attributes
 # stored by an Element or SubElement.
-attributes = Table('attributes', meta,
-    Column('element_id', Integer, ForeignKey('elements.element_id'), primary_key=True),
-    Column('name', Unicode(100), nullable=False, primary_key=True),
-    Column('value', Unicode(255)))
+attributes = Table(
+    "attributes",
+    meta,
+    Column(
+        "element_id",
+        Integer,
+        ForeignKey("elements.element_id"),
+        primary_key=True,
+    ),
+    Column("name", Unicode(100), nullable=False, primary_key=True),
+    Column("value", Unicode(255)),
+)
 
 meta.create_all(e)
 
@@ -68,6 +89,7 @@ class Document(object):
         self.element.write(buf)
         return buf.getvalue()
 
+
 #################################### PART IV - Persistence Mapping #################################
 
 # Node class.  a non-public class which will represent
@@ -78,6 +100,7 @@ class Document(object):
 class _Node(object):
     pass
 
+
 # Attribute class.  also internal, this will represent the key/value attributes stored for
 # a particular Node.
 class _Attribute(object):
@@ -85,16 +108,25 @@ class _Attribute(object):
         self.name = name
         self.value = value
 
+
 # setup mappers.  Document will eagerly load a list of _Node objects.
-mapper(Document, documents, properties={
-    '_root':relationship(_Node, lazy='joined', cascade="all")
-})
+mapper(
+    Document,
+    documents,
+    properties={"_root": relationship(_Node, lazy="joined", cascade="all")},
+)
 
-mapper(_Node, elements, properties={
-    'children':relationship(_Node, cascade="all"),
-    # eagerly load attributes
-    'attributes':relationship(_Attribute, lazy='joined', cascade="all, delete-orphan"),
-})
+mapper(
+    _Node,
+    elements,
+    properties={
+        "children": relationship(_Node, cascade="all"),
+        # eagerly load attributes
+        "attributes": relationship(
+            _Attribute, lazy="joined", cascade="all, delete-orphan"
+        ),
+    },
+)
 
 mapper(_Attribute, attributes)
 
@@ -106,7 +138,7 @@ class ElementTreeMarshal(object):
         if document is None:
             return self
 
-        if hasattr(document, '_element'):
+        if hasattr(document, "_element"):
             return document._element
 
         def traverse(node, parent=None):
@@ -132,7 +164,9 @@ class ElementTreeMarshal(object):
             n.text = str(node.text)
             n.tail = str(node.tail)
             n.children = [traverse(n2) for n2 in node]
-            n.attributes = [_Attribute(str(k), str(v)) for k, v in node.attrib.items()]
+            n.attributes = [
+                _Attribute(str(k), str(v)) for k, v in node.attrib.items()
+            ]
             return n
 
         document._root = traverse(element.getroot())
@@ -142,6 +176,7 @@ class ElementTreeMarshal(object):
         del document._element
         document._root = []
 
+
 # override Document's "element" attribute with the marshaller.
 Document.element = ElementTreeMarshal()
 
@@ -153,7 +188,7 @@ line = "\n--------------------------------------------------------"
 session = Session(e)
 
 # get ElementTree documents
-for file in ('test.xml', 'test2.xml', 'test3.xml'):
+for file in ("test.xml", "test2.xml", "test3.xml"):
     filename = os.path.join(os.path.dirname(__file__), file)
     doc = ElementTree.parse(filename)
     session.add(Document(file, doc))
@@ -170,10 +205,16 @@ print(document)
 ############################################ PART VI - Searching for Paths #########################
 
 # manually search for a document which contains "/somefile/header/field1:hi"
-d = session.query(Document).join('_root', aliased=True).filter(_Node.tag=='somefile').\
-    join('children', aliased=True, from_joinpoint=True).filter(_Node.tag=='header').\
-    join('children', aliased=True, from_joinpoint=True).filter(
-            and_(_Node.tag=='field1', _Node.text=='hi')).one()
+d = (
+    session.query(Document)
+    .join("_root", aliased=True)
+    .filter(_Node.tag == "somefile")
+    .join("children", aliased=True, from_joinpoint=True)
+    .filter(_Node.tag == "header")
+    .join("children", aliased=True, from_joinpoint=True)
+    .filter(and_(_Node.tag == "field1", _Node.text == "hi"))
+    .one()
+)
 print(d)
 
 # generalize the above approach into an extremely impoverished xpath function:
@@ -181,26 +222,39 @@ def find_document(path, compareto):
     j = documents
     prev_elements = None
     query = session.query(Document)
-    attribute = '_root'
-    for i, match in enumerate(re.finditer(r'/([\w_]+)(?:\[@([\w_]+)(?:=(.*))?\])?', path)):
+    attribute = "_root"
+    for i, match in enumerate(
+        re.finditer(r"/([\w_]+)(?:\[@([\w_]+)(?:=(.*))?\])?", path)
+    ):
         (token, attrname, attrvalue) = match.group(1, 2, 3)
-        query = query.join(attribute, aliased=True, from_joinpoint=True).filter(_Node.tag==token)
-        attribute = 'children'
+        query = query.join(
+            attribute, aliased=True, from_joinpoint=True
+        ).filter(_Node.tag == token)
+        attribute = "children"
         if attrname:
             if attrvalue:
-                query = query.join('attributes', aliased=True, from_joinpoint=True).filter(
-                        and_(_Attribute.name==attrname, _Attribute.value==attrvalue))
+                query = query.join(
+                    "attributes", aliased=True, from_joinpoint=True
+                ).filter(
+                    and_(
+                        _Attribute.name == attrname,
+                        _Attribute.value == attrvalue,
+                    )
+                )
             else:
-                query = query.join('attributes', aliased=True, from_joinpoint=True).filter(
-                        _Attribute.name==attrname)
-    return query.options(lazyload('_root')).filter(_Node.text==compareto).all()
+                query = query.join(
+                    "attributes", aliased=True, from_joinpoint=True
+                ).filter(_Attribute.name == attrname)
+    return (
+        query.options(lazyload("_root")).filter(_Node.text == compareto).all()
+    )
+
 
 for path, compareto in (
-        ('/somefile/header/field1', 'hi'),
-        ('/somefile/field1', 'hi'),
-        ('/somefile/header/field2', 'there'),
-        ('/somefile/header/field2[@attr=foo]', 'there')
-    ):
+    ("/somefile/header/field1", "hi"),
+    ("/somefile/field1", "hi"),
+    ("/somefile/header/field2", "there"),
+    ("/somefile/header/field2[@attr=foo]", "there"),
+):
     print("\nDocuments containing '%s=%s':" % (path, compareto), line)
     print([d.filename for d in find_document(path, compareto)])
-
diff --git a/examples/elementtree/optimized_al.py b/examples/elementtree/optimized_al.py
index e13f5b0ee..8e9c48b96 100644
--- a/examples/elementtree/optimized_al.py
+++ b/examples/elementtree/optimized_al.py
@@ -8,42 +8,63 @@
 """
 
 ##################### PART I - Imports/Configuration #########################
-from sqlalchemy import (MetaData, Table, Column, Integer, String, ForeignKey,
-    Unicode, and_, create_engine)
+from sqlalchemy import (
+    MetaData,
+    Table,
+    Column,
+    Integer,
+    String,
+    ForeignKey,
+    Unicode,
+    and_,
+    create_engine,
+)
 from sqlalchemy.orm import mapper, relationship, Session, lazyload
 
 import sys, os, io, re
 
 from xml.etree import ElementTree
 
-e = create_engine('sqlite://', echo=True)
+e = create_engine("sqlite://", echo=True)
 meta = MetaData()
 
 ####################### PART II - Table Metadata #############################
 
 # stores a top level record of an XML document.
-documents = Table('documents', meta,
-    Column('document_id', Integer, primary_key=True),
-    Column('filename', String(30), unique=True),
+documents = Table(
+    "documents",
+    meta,
+    Column("document_id", Integer, primary_key=True),
+    Column("filename", String(30), unique=True),
 )
 
 # stores XML nodes in an adjacency list model.  This corresponds to
 # Element and SubElement objects.
-elements = Table('elements', meta,
-    Column('element_id', Integer, primary_key=True),
-    Column('parent_id', Integer, ForeignKey('elements.element_id')),
-    Column('document_id', Integer, ForeignKey('documents.document_id')),
-    Column('tag', Unicode(30), nullable=False),
-    Column('text', Unicode),
-    Column('tail', Unicode)
-    )
+elements = Table(
+    "elements",
+    meta,
+    Column("element_id", Integer, primary_key=True),
+    Column("parent_id", Integer, ForeignKey("elements.element_id")),
+    Column("document_id", Integer, ForeignKey("documents.document_id")),
+    Column("tag", Unicode(30), nullable=False),
+    Column("text", Unicode),
+    Column("tail", Unicode),
+)
 
 # stores attributes.  This corresponds to the dictionary of attributes
 # stored by an Element or SubElement.
-attributes = Table('attributes', meta,
-    Column('element_id', Integer, ForeignKey('elements.element_id'), primary_key=True),
-    Column('name', Unicode(100), nullable=False, primary_key=True),
-    Column('value', Unicode(255)))
+attributes = Table(
+    "attributes",
+    meta,
+    Column(
+        "element_id",
+        Integer,
+        ForeignKey("elements.element_id"),
+        primary_key=True,
+    ),
+    Column("name", Unicode(100), nullable=False, primary_key=True),
+    Column("value", Unicode(255)),
+)
 
 meta.create_all(e)
 
@@ -61,6 +82,7 @@ class Document(object):
         self.element.write(buf)
         return buf.getvalue()
 
+
 ########################## PART IV - Persistence Mapping #####################
 
 # Node class.  a non-public class which will represent
@@ -71,6 +93,7 @@ class Document(object):
 class _Node(object):
     pass
 
+
 # Attribute class.  also internal, this will represent the key/value attributes stored for
 # a particular Node.
 class _Attribute(object):
@@ -78,21 +101,36 @@ class _Attribute(object):
         self.name = name
         self.value = value
 
+
 # setup mappers.  Document will eagerly load a list of _Node objects.
 # they will be ordered in primary key/insert order, so that we can reconstruct
 # an ElementTree structure from the list.
-mapper(Document, documents, properties={
-    '_nodes':relationship(_Node, lazy='joined', cascade="all, delete-orphan")
-})
+mapper(
+    Document,
+    documents,
+    properties={
+        "_nodes": relationship(
+            _Node, lazy="joined", cascade="all, delete-orphan"
+        )
+    },
+)
 
 # the _Node objects change the way they load so that a list of _Nodes will organize
 # themselves hierarchically using the ElementTreeMarshal.  this depends on the ordering of
 # nodes being hierarchical as well; relationship() always applies at least ROWID/primary key
 # ordering to rows which will suffice.
-mapper(_Node, elements, properties={
-    'children':relationship(_Node, lazy=None),  # doesnt load; used only for the save relationship
-    'attributes':relationship(_Attribute, lazy='joined', cascade="all, delete-orphan"), # eagerly load attributes
-})
+mapper(
+    _Node,
+    elements,
+    properties={
+        "children": relationship(
+            _Node, lazy=None
+        ),  # doesnt load; used only for the save relationship
+        "attributes": relationship(
+            _Attribute, lazy="joined", cascade="all, delete-orphan"
+        ),  # eagerly load attributes
+    },
+)
 
 mapper(_Attribute, attributes)
 
@@ -104,7 +142,7 @@ class ElementTreeMarshal(object):
         if document is None:
             return self
 
-        if hasattr(document, '_element'):
+        if hasattr(document, "_element"):
             return document._element
 
         nodes = {}
@@ -134,7 +172,9 @@ class ElementTreeMarshal(object):
             n.tail = str(node.tail)
             document._nodes.append(n)
             n.children = [traverse(n2) for n2 in node]
-            n.attributes = [_Attribute(str(k), str(v)) for k, v in node.attrib.items()]
+            n.attributes = [
+                _Attribute(str(k), str(v)) for k, v in node.attrib.items()
+            ]
             return n
 
         traverse(element.getroot())
@@ -144,6 +184,7 @@ class ElementTreeMarshal(object):
         del document._element
         document._nodes = []
 
+
 # override Document's "element" attribute with the marshaller.
 Document.element = ElementTreeMarshal()
 
@@ -155,7 +196,7 @@ line = "\n--------------------------------------------------------"
 session = Session(e)
 
 # get ElementTree documents
-for file in ('test.xml', 'test2.xml', 'test3.xml'):
+for file in ("test.xml", "test2.xml", "test3.xml"):
     filename = os.path.join(os.path.dirname(__file__), file)
     doc = ElementTree.parse(filename)
     session.add(Document(file, doc))
@@ -173,13 +214,16 @@ print(document)
 
 # manually search for a document which contains "/somefile/header/field1:hi"
 print("\nManual search for /somefile/header/field1=='hi':", line)
-d = session.query(Document).join('_nodes', aliased=True).\
-                filter(and_(_Node.parent_id==None, _Node.tag=='somefile')).\
-                join('children', aliased=True, from_joinpoint=True).\
-                filter(_Node.tag=='header').\
-                join('children', aliased=True, from_joinpoint=True).\
-                filter(and_(_Node.tag=='field1', _Node.text=='hi')).\
-                one()
+d = (
+    session.query(Document)
+    .join("_nodes", aliased=True)
+    .filter(and_(_Node.parent_id == None, _Node.tag == "somefile"))
+    .join("children", aliased=True, from_joinpoint=True)
+    .filter(_Node.tag == "header")
+    .join("children", aliased=True, from_joinpoint=True)
+    .filter(and_(_Node.tag == "field1", _Node.text == "hi"))
+    .one()
+)
 print(d)
 
 # generalize the above approach into an extremely impoverished xpath function:
@@ -188,28 +232,39 @@ def find_document(path, compareto):
     prev_elements = None
     query = session.query(Document)
     first = True
-    for i, match in enumerate(re.finditer(r'/([\w_]+)(?:\[@([\w_]+)(?:=(.*))?\])?', path)):
+    for i, match in enumerate(
+        re.finditer(r"/([\w_]+)(?:\[@([\w_]+)(?:=(.*))?\])?", path)
+    ):
         (token, attrname, attrvalue) = match.group(1, 2, 3)
         if first:
-            query = query.join('_nodes', aliased=True).filter(_Node.parent_id==None)
+            query = query.join("_nodes", aliased=True).filter(
+                _Node.parent_id == None
+            )
             first = False
         else:
-            query = query.join('children', aliased=True, from_joinpoint=True)
-        query = query.filter(_Node.tag==token)
+            query = query.join("children", aliased=True, from_joinpoint=True)
+        query = query.filter(_Node.tag == token)
         if attrname:
-            query = query.join('attributes', aliased=True, from_joinpoint=True)
+            query = query.join("attributes", aliased=True, from_joinpoint=True)
             if attrvalue:
-                query = query.filter(and_(_Attribute.name==attrname, _Attribute.value==attrvalue))
+                query = query.filter(
+                    and_(
+                        _Attribute.name == attrname,
+                        _Attribute.value == attrvalue,
+                    )
+                )
             else:
-                query = query.filter(_Attribute.name==attrname)
-    return query.options(lazyload('_nodes')).filter(_Node.text==compareto).all()
+                query = query.filter(_Attribute.name == attrname)
+    return (
+        query.options(lazyload("_nodes")).filter(_Node.text == compareto).all()
+    )
+
 
 for path, compareto in (
-        ('/somefile/header/field1', 'hi'),
-        ('/somefile/field1', 'hi'),
-        ('/somefile/header/field2', 'there'),
-        ('/somefile/header/field2[@attr=foo]', 'there')
-    ):
+    ("/somefile/header/field1", "hi"),
+    ("/somefile/field1", "hi"),
+    ("/somefile/header/field2", "there"),
+    ("/somefile/header/field2[@attr=foo]", "there"),
+):
     print("\nDocuments containing '%s=%s':" % (path, compareto), line)
     print([d.filename for d in find_document(path, compareto)])
-
diff --git a/examples/elementtree/pickle.py b/examples/elementtree/pickle.py
index d40af275b..a86fe30e5 100644
--- a/examples/elementtree/pickle.py
+++ b/examples/elementtree/pickle.py
@@ -6,15 +6,22 @@ structure in distinct rows using two additional mapped entities.  Note that the
 styles of persistence are identical, as is the structure of the main Document class.
 """
 
-from sqlalchemy import (create_engine, MetaData, Table, Column, Integer, String,
-    PickleType)
+from sqlalchemy import (
+    create_engine,
+    MetaData,
+    Table,
+    Column,
+    Integer,
+    String,
+    PickleType,
+)
 from sqlalchemy.orm import mapper, Session
 
 import sys, os
 
 from xml.etree import ElementTree
 
-e = create_engine('sqlite://')
+e = create_engine("sqlite://")
 meta = MetaData()
 
 # setup a comparator for the PickleType since it's a mutable
@@ -22,12 +29,15 @@ meta = MetaData()
 def are_elements_equal(x, y):
     return x == y
 
+
 # stores a top level record of an XML document.
 # the "element" column will store the ElementTree document as a BLOB.
-documents = Table('documents', meta,
-    Column('document_id', Integer, primary_key=True),
-    Column('filename', String(30), unique=True),
-    Column('element', PickleType(comparator=are_elements_equal))
+documents = Table(
+    "documents",
+    meta,
+    Column("document_id", Integer, primary_key=True),
+    Column("filename", String(30), unique=True),
+    Column("element", PickleType(comparator=are_elements_equal)),
 )
 
 meta.create_all(e)
@@ -39,6 +49,7 @@ class Document(object):
         self.filename = name
         self.element = element
 
+
 # setup mapper.
 mapper(Document, documents)
 
@@ -58,4 +69,3 @@ document = session.query(Document).filter_by(filename="test.xml").first()
 
 # print
 document.element.write(sys.stdout)
-