DOCSP-46812 - Distribute Type Hints (#167)

Author: mongoKart

source/aggregation/aggregation-tutorials/filtered-subset.txt

@@ -90,9 +90,7 @@ Tutorial
       Next, add a :manual:`$sort
       </reference/operator/aggregation/sort>` stage that sorts the
       documents in descending order by the ``dateofbirth`` field to
-      list the youngest people first. Because Python dictionaries don't maintain the
-      order of their elements, use a ``SON``or ``OrderedDict`` object
-      instead:
+      list the youngest people first:
 
       .. literalinclude:: /includes/aggregation/filtered-subset.py
          :language: python

source/connect/mongoclient.txt

@@ -119,7 +119,7 @@ constructor accepts. All parameters are optional.
        :wikipedia:`round-robin DNS <Round-robin_DNS>` addresses.
 
        **Data type:** ``Union[str, Sequence[str]]``
-       **Default value:** ``"localhost"``
+       | **Default value:** ``"localhost"``
 
    * - ``port``
      - The port number {+mdb-server+} is running on.
@@ -128,17 +128,35 @@ constructor accepts. All parameters are optional.
        instead of using this parameter.
 
        **Data type:** ``int``
-       **Default value:** ``27017``
+       | **Default value:** ``27017``
 
    * - ``document_class``
      - The default class that the client uses to decode BSON documents returned by queries.
-       This parameter supports the ``bson.raw_bson.RawBSONDocument`` type, as well as
-       subclasses of the ``collections.abc.Mapping`` type, such as ``bson.son.SON``.
+       This parameter accepts the following types:
 
-       If you specify ``bson.son.SON`` as the document class, you must also specify types
-       for the key and value.
+       - ``bson.raw_bson.RawBSONDocument``. To learn more about the ``RawBSONDocument`` class,
+         see :ref:`pymongo-bson-raw`.
+
+       - A subclass of the ``collections.abc.Mapping`` type, such as ``OrderedDict``.
+         Depending on the strictness of your type-checking rules, you might also need to
+         specify types for the key and value, as shown in the following example:
+
+         .. code-block:: python
+
+            client = MongoClient(document_class=OrderedDict[str, int])
+       
+       - A subclass of the ``TypedDict`` type. To pass a ``TypedDict`` subclass for this
+         parameter, you must also include the class in a type hint for your ``MongoClient``
+         object, as shown in the following example:
+
+         .. code-block:: python
+
+            client: MongoClient[MyTypedDict] = MongoClient() 
+
+         .. include:: /includes/type-hints/typeddict-availability.rst
 
        **Data type:** ``Type[_DocumentType]``
+       **Default:** ``dict``
 
    * - ``tz_aware``
      - If this parameter is ``True``, the client treats ``datetime`` values as aware.
@@ -231,28 +249,46 @@ To use multiprocessing with {+driver-short+}, write code similar to the followin
    Do not copy an instance of the ``MongoClient`` class from the parent process to a child
    process.
 
-Type Hints
+.. _pymongo-type-hints-client:
+
+Type Hints 
 ----------
 
-If you're using Python v3.5 or later, you can add type hints to your Python code.
+.. include:: /includes/type-hints/intro.rst
 
-The following code example shows how to declare a type hint for a ``MongoClient``
-object:
+To use type hints in your {+driver-short+} application, you must add a type annotation to your
+``MongoClient`` object, as shown in the following example:
 
 .. code-block:: python
 
    client: MongoClient = MongoClient()
 
-In the previous example, the code doesn't specify a type for the documents that the
-``MongoClient`` object will work with. To specify a document type,
-include the ``Dict[str, Any]`` type when you
-create the ``MongoClient`` object, as shown in the following example:
+For more accurate type information, you can include the generic document type
+``Dict[str, Any]`` in your type annotation. This data type matches all documents in MongoDB.
+The following example shows how to include this data type in your type annotation:
 
 .. code-block:: python
 
    from typing import Any, Dict
    client: MongoClient[Dict[str, Any]] = MongoClient()
 
+If all the documents that you are working with correspond to a single custom type, you
+can specify the custom type as a type hint for your ``MongoClient`` object. This
+provides more accurate type information than the generic ``Dict[str, Any]`` type.
+
+The following example shows how to specify the ``Movie`` type as a type hint for a
+``MongoClient`` object:
+
+.. code-block:: python
+
+   from typing import TypedDict
+
+   class Movie(TypedDict):
+       name: str
+       year: int
+   
+   client: MongoClient[Movie] = MongoClient()
+
 Troubleshooting
 ---------------
 
@@ -317,10 +353,14 @@ process.
    multithreaded contexts with ``fork()``, see `Issue 6721 <http://bugs.python.org/issue6721>`__
    in the Python Issue Tracker.
 
+.. include:: /includes/type-hints/troubleshooting-client-type.rst
+
+.. include:: /includes/type-hints/troubleshooting-incompatible-type.rst
+
 API Documentation
 -----------------
 
 To learn more about creating a ``MongoClient`` object in {+driver-short+},
 see the following API documentation:
 
-- `MongoClient <{+api-root+}pymongo/mongo_client.html#pymongo.mongo_client.MongoClient>`__ 
+- `MongoClient <{+api-root+}pymongo/mongo_client.html#pymongo.mongo_client.MongoClient>`__

source/data-formats/bson.txt

@@ -117,6 +117,8 @@ The following example reads the sample BSON document from ``file.bson``:
 
       {"address": {"street": "Pizza St", "zipcode": "10003"}, "coord": [-73.982419, 41.579505], "cuisine": "Pizza", "name": "Mongo's Pizza"}
 
+.. _pymongo-bson-raw:
+
 Work with Raw BSON Data
 -----------------------
 

source/databases-collections.txt

@@ -321,9 +321,79 @@ To learn more about supported retryable read operations, see :manual:`Retryable
 in the {+mdb-server+} manual. To learn more about supported retryable write
 operations, see :manual:`Retryable Writes </core/retryable-writes/>` in the {+mdb-server+} manual.
 
+.. _pymongo-databases-collection-type-hints:
+
+Type Hints
+----------
+
+.. include:: /includes/type-hints/intro.rst
+
+.. note:: TypedDict in Python 3.7 and Earlier
+   
+   .. include:: /includes/type-hints/typeddict-availability.rst
+
+Database
+~~~~~~~~
+
+If all documents in a database match a well-defined schema, you can specify a type hint
+that uses a Python class to represent the documents' structure. By including this class
+in the type hint for your ``Database`` object, you can ensure that all documents you
+store or retrieve have the required structure. This provides more accurate type
+checking and code completion than the default ``Dict[str, Any]`` type.
+
+First, define a class to represent a document from the database. The class must inherit
+from the ``TypedDict`` class and must contain the same fields as the documents in the
+database. After you define your class, include its name as the generic type for the
+``Database`` type hint.
+
+The following example defines a ``Movie`` class and uses it as the
+generic type for a ``Database`` type hint:
+
+.. code-block:: python
+   :emphasize-lines: 5-7, 10
+
+   from typing import TypedDict
+   from pymongo import MongoClient
+   from pymongo.database import Database
+
+   class Movie(TypedDict):
+       name: str
+       year: int
+   
+   client: MongoClient = MongoClient()
+   database: Database[Movie] = client["test_database"]
+
+Collection
+~~~~~~~~~~
+
+Adding a generic type to a ``Collection`` type hint is similar to adding a generic type
+to a ``Database`` type hint. First, define a class that inherits from the ``TypedDict`` class
+and represents the structure of the
+documents in the collection. Then, include the class name as the generic type for the
+``Collection`` type hint, as shown in the following example:
+
+.. code-block:: python
+   :emphasize-lines: 5-7,11
+
+   from typing import TypedDict
+   from pymongo import MongoClient
+   from pymongo.collection import Collection
+   
+   class Movie(TypedDict):
+       name: str
+       year: int
+   
+   client: MongoClient = MongoClient()
+   database = client["test_database"]
+   collection: Collection[Movie] = database["test_collection"]
+
 Troubleshooting
 ---------------
 
+.. include:: /includes/type-hints/troubleshooting-client-type.rst
+
+.. include:: /includes/type-hints/troubleshooting-incompatible-type.rst
+
 .. include:: /includes/troubleshooting/read-write-options.rst
 
 API Documentation