PYTHON-5129 - Fix async transaction docstrings (#2138)

Author: NoahStapp

pymongo/asynchronous/client_session.py

@@ -21,7 +21,7 @@
 
 .. code-block:: python
 
-  with client.start_session(causal_consistency=True) as session:
+  async with client.start_session(causal_consistency=True) as session:
       collection = client.db.collection
       await collection.update_one({"_id": 1}, {"$set": {"x": 10}}, session=session)
       secondary_c = collection.with_options(read_preference=ReadPreference.SECONDARY)
@@ -53,16 +53,16 @@
 
   orders = client.db.orders
   inventory = client.db.inventory
-  with client.start_session() as session:
-      async with session.start_transaction():
+  async with client.start_session() as session:
+      async with await session.start_transaction():
           await orders.insert_one({"sku": "abc123", "qty": 100}, session=session)
           await inventory.update_one(
               {"sku": "abc123", "qty": {"$gte": 100}},
               {"$inc": {"qty": -100}},
               session=session,
           )
 
-Upon normal completion of ``async with session.start_transaction()`` block, the
+Upon normal completion of ``async with await session.start_transaction()`` block, the
 transaction automatically calls :meth:`AsyncClientSession.commit_transaction`.
 If the block exits with an exception, the transaction automatically calls
 :meth:`AsyncClientSession.abort_transaction`.
@@ -113,7 +113,7 @@
 .. code-block:: python
 
   # Each read using this session reads data from the same point in time.
-  with client.start_session(snapshot=True) as session:
+  async with client.start_session(snapshot=True) as session:
       order = await orders.find_one({"sku": "abc123"}, session=session)
       inventory = await inventory.find_one({"sku": "abc123"}, session=session)
 
@@ -619,7 +619,7 @@ async def callback(session):
               await inventory.update_one({"sku": "abc123", "qty": {"$gte": 100}},
                                    {"$inc": {"qty": -100}}, session=session)
 
-          with client.start_session() as session:
+          async with client.start_session() as session:
               await session.with_transaction(callback)
 
         To pass arbitrary arguments to the ``callback``, wrap your callable
@@ -628,7 +628,7 @@ async def callback(session):
           async def callback(session, custom_arg, custom_kwarg=None):
               # Transaction operations...
 
-          with client.start_session() as session:
+          async with client.start_session() as session:
               await session.with_transaction(
                   lambda s: callback(s, "custom_arg", custom_kwarg=1))