pep-484 for engine

All modules in sqlalchemy.engine are strictly
typed with the exception of cursor, default, and
reflection.  cursor and default pass with non-strict
typing, reflection is waiting on the multi-reflection
refactor.

Behavioral changes:

* create_connect_args() methods return a tuple of list,
  dict, rather than a list of list, dict
* removed allow_chars parameter from
  pyodbc connector ._get_server_version_info()
  method
* the parameter list passed to do_executemany is now
  a list in all cases. previously, this was being run
  through dialect.execute_sequence_format, which
  defaults to tuple and was only intended for individual
  tuple params.
* broke up dialect.dbapi into dialect.import_dbapi
  class method and dialect.dbapi module object.  added
  a deprecation path for legacy dialects.  it's not
  really feasible to type a single attr as a classmethod
  vs. module type.  The "type_compiler" attribute also
  has this problem with greater ability to work around,
  left that one for now.
* lots of constants changing to be Enum, so that we can
  type them.  for fixed tuple-position constants in
  cursor.py / compiler.py (which are used to avoid the
  speed overhead of namedtuple), using Literal[value]
  which seems to work well
* some tightening up in Row regarding __getitem__, which
  we can do since we are on full 2.0 style result use
* altered the set_connection_execution_options and
  set_engine_execution_options event flows so that the
  dictionary of options may be mutated within the event
  hook, where it will then take effect as the actual
  options used.  Previously, changing the dict would
  be silently ignored which seems counter-intuitive
  and not very useful.
* A lot of DefaultDialect/DefaultExecutionContext
  methods and attributes, including underscored ones, move
  to interfaces.  This is not fully ideal as it means
  the Dialect/ExecutionContext interfaces aren't publicly
  subclassable directly, but their current purpose
  is more of documentation for dialect authors who should
  (and certainly are) still be subclassing the DefaultXYZ
  versions in all cases

Overall, Result was the most extremely difficult class
hierarchy to type here as this hierarchy passes through
largely amorphous "row" datatypes throughout, which
can in fact by all kinds of different things, like
raw DBAPI rows, or Row objects, or "scalar"/Any, but
at the same time these types have meaning so I tried still
maintaining some level of semantic markings for these,
it highlights how complex Result is now, as it's trying
to be extremely efficient and inlined while also being
very open-ended and extensible.

Change-Id: I98b75c0c09eab5355fc7a33ba41dd9874274f12a

3 files changed, 8 insertions, 8 deletions

diff --git a/doc/build/tutorial/data_insert.rst b/doc/build/tutorial/data_insert.rst
index 74b0aff56..a8b1a49a2 100644
--- a/doc/build/tutorial/data_insert.rst
+++ b/doc/build/tutorial/data_insert.rst
@@ -127,7 +127,7 @@ illustrate this:
     ...     conn.commit()
     {opensql}BEGIN (implicit)
     INSERT INTO user_account (name, fullname) VALUES (?, ?)
-    [...] (('sandy', 'Sandy Cheeks'), ('patrick', 'Patrick Star'))
+    [...] [('sandy', 'Sandy Cheeks'), ('patrick', 'Patrick Star')]
     COMMIT{stop}
 
 The execution above features "executemany" form first illustrated at
@@ -185,8 +185,8 @@ construct automatically.
         INSERT INTO address (user_id, email_address) VALUES ((SELECT user_account.id
         FROM user_account
         WHERE user_account.name = ?), ?)
-        [...] (('spongebob', 'spongebob@sqlalchemy.org'), ('sandy', 'sandy@sqlalchemy.org'),
-        ('sandy', 'sandy@squirrelpower.org'))
+        [...] [('spongebob', 'spongebob@sqlalchemy.org'), ('sandy', 'sandy@sqlalchemy.org'),
+        ('sandy', 'sandy@squirrelpower.org')]
         COMMIT{stop}
 
 .. _tutorial_insert_from_select:
diff --git a/doc/build/tutorial/data_update.rst b/doc/build/tutorial/data_update.rst
index 8813dda98..8e88eb2f7 100644
--- a/doc/build/tutorial/data_update.rst
+++ b/doc/build/tutorial/data_update.rst
@@ -101,7 +101,7 @@ that literal values would normally go:
     ...   )
     {opensql}BEGIN (implicit)
     UPDATE user_account SET name=? WHERE user_account.name = ?
-    [...] (('ed', 'jack'), ('mary', 'wendy'), ('jake', 'jim'))
+    [...] [('ed', 'jack'), ('mary', 'wendy'), ('jake', 'jim')]
     <sqlalchemy.engine.cursor.CursorResult object at 0x...>
     COMMIT{stop}
 
diff --git a/doc/build/tutorial/dbapi_transactions.rst b/doc/build/tutorial/dbapi_transactions.rst
index 16768da2b..f4d2ad8e0 100644
--- a/doc/build/tutorial/dbapi_transactions.rst
+++ b/doc/build/tutorial/dbapi_transactions.rst
@@ -115,7 +115,7 @@ where we acquired the :class:`_future.Connection` object:
     [...] ()
     <sqlalchemy.engine.cursor.CursorResult object at 0x...>
     INSERT INTO some_table (x, y) VALUES (?, ?)
-    [...] ((1, 1), (2, 4))
+    [...] [(1, 1), (2, 4)]
     <sqlalchemy.engine.cursor.CursorResult object at 0x...>
     COMMIT
 
@@ -149,7 +149,7 @@ may be referred towards as **begin once**:
     ...     )
     {opensql}BEGIN (implicit)
     INSERT INTO some_table (x, y) VALUES (?, ?)
-    [...] ((6, 8), (9, 10))
+    [...] [(6, 8), (9, 10)]
     <sqlalchemy.engine.cursor.CursorResult object at 0x...>
     COMMIT
 
@@ -374,7 +374,7 @@ be invoked against each parameter set individually:
     ...     conn.commit()
     {opensql}BEGIN (implicit)
     INSERT INTO some_table (x, y) VALUES (?, ?)
-    [...] ((11, 12), (13, 14))
+    [...] [(11, 12), (13, 14)]
     <sqlalchemy.engine.cursor.CursorResult object at 0x...>
     COMMIT
 
@@ -508,7 +508,7 @@ our data:
     ...     session.commit()
     {opensql}BEGIN (implicit)
     UPDATE some_table SET y=? WHERE x=?
-    [...] ((11, 9), (15, 13))
+    [...] [(11, 9), (15, 13)]
     COMMIT{stop}
 
 Above, we invoked an UPDATE statement using the bound-parameter, "executemany"