Tidied up session interface to make access_mode a kwarg

neo4j · Feb 1, 2019 · 9d28038 · 9d28038
1 parent dc08642
commit 9d28038
Show file tree

Hide file tree

Showing 3 changed files with 28 additions and 18 deletions.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -4,3 +4,4 @@
 - Package can now no longer be installed as `neo4j-driver`; use `pip install neo4j` instead
 - Support dropped for Python 2.7; explicit support added for Python 3.7 and 3.8
 - The `neo4j.v1` subpackage is now no longer available; all imports should be taken from the `neo4j` package instead
+- Changed `session(access_mode)` from a positional to a keyword argument
diff --git a/neo4j/__init__.py b/neo4j/__init__.py
@@ -153,18 +153,25 @@ def __enter__(self):
     def __exit__(self, exc_type, exc_value, traceback):
         self.close()
 
-    def session(self, access_mode=None, **parameters):
+    def _assert_open(self):
+        if self.closed():
+            raise DriverError("Driver closed")
+
+    def session(self, **parameters):
         """ Create a new :class:`.Session` object based on this
         :class:`.Driver`.
 
-        :param access_mode: default access mode (read or write) for
-                            transactions in this session
         :param parameters: custom session parameters (see
                            :class:`.Session` for details)
         :returns: new :class:`.Session` object
         """
-        if self.closed():
-            raise DriverError("Driver closed")
+        raise NotImplementedError("Blocking sessions are not implemented for the %s class" % type(self).__name__)
+
+    def async_session(self, **parameters):
+        raise NotImplementedError("Asynchronous sessions are not implemented for the %s class" % type(self).__name__)
+
+    def rx_session(self, **parameters):
+        raise NotImplementedError("Reactive sessions are not implemented for the %s class" % type(self).__name__)
 
     def close(self):
         """ Shut down, closing any open connections in the pool.
@@ -220,10 +227,11 @@ def connector(address, **kwargs):
         instance._max_retry_time = config.get("max_retry_time", default_config["max_retry_time"])
         return instance
 
-    def session(self, access_mode=None, **parameters):
+    def session(self, **parameters):
+        self._assert_open()
         if "max_retry_time" not in parameters:
             parameters["max_retry_time"] = self._max_retry_time
-        return Session(self._pool.acquire, access_mode, **parameters)
+        return Session(self._pool.acquire, **parameters)
 
 
 class RoutingDriver(Driver):
@@ -267,10 +275,11 @@ def connector(address, **kwargs):
             instance._max_retry_time = config.get("max_retry_time", default_config["max_retry_time"])
             return instance
 
-    def session(self, access_mode=None, **parameters):
+    def session(self, **parameters):
+        self._assert_open()
         if "max_retry_time" not in parameters:
             parameters["max_retry_time"] = self._max_retry_time
-        return Session(self._pool.acquire, access_mode, **parameters)
+        return Session(self._pool.acquire, **parameters)
 
 
 class Session(object):
@@ -332,9 +341,9 @@ class Session(object):
 
     _closed = False
 
-    def __init__(self, acquirer, access_mode, **parameters):
+    def __init__(self, acquirer, **parameters):
         self._acquirer = acquirer
-        self._default_access_mode = access_mode
+        self._default_access_mode = parameters.get("access_mode")
         for key, value in parameters.items():
             if key == "bookmark":
                 if value:

diff --git a/test/stub/test_routingdriver.py b/test/stub/test_routingdriver.py
@@ -188,7 +188,7 @@ def test_should_call_get_routing_table_procedure(self):
         with StubCluster({9001: "get_routing_table.script", 9002: "return_1.script"}):
             uri = "bolt+routing://127.0.0.1:9001"
             with GraphDatabase.driver(uri, auth=self.auth_token, encrypted=False) as driver:
-                with driver.session(READ_ACCESS) as session:
+                with driver.session(access_mode=READ_ACCESS) as session:
                     result = session.run("RETURN $x", {"x": 1})
                     for record in result:
                         assert record["x"] == 1
@@ -198,7 +198,7 @@ def test_should_call_get_routing_table_with_context(self):
         with StubCluster({9001: "get_routing_table_with_context.script", 9002: "return_1.script"}):
             uri = "bolt+routing://127.0.0.1:9001/?name=molly&age=1"
             with GraphDatabase.driver(uri, auth=self.auth_token, encrypted=False) as driver:
-                with driver.session(READ_ACCESS) as session:
+                with driver.session(access_mode=READ_ACCESS) as session:
                     result = session.run("RETURN $x", {"x": 1})
                     for record in result:
                         assert record["x"] == 1
@@ -208,7 +208,7 @@ def test_should_serve_read_when_missing_writer(self):
         with StubCluster({9001: "router_no_writers.script", 9005: "return_1.script"}):
             uri = "bolt+routing://127.0.0.1:9001"
             with GraphDatabase.driver(uri, auth=self.auth_token, encrypted=False) as driver:
-                with driver.session(READ_ACCESS) as session:
+                with driver.session(access_mode=READ_ACCESS) as session:
                     result = session.run("RETURN $x", {"x": 1})
                     for record in result:
                         assert record["x"] == 1
@@ -249,7 +249,7 @@ def test_forgets_address_on_not_a_leader_error(self):
         with StubCluster({9001: "router.script", 9006: "not_a_leader.script"}):
             uri = "bolt+routing://127.0.0.1:9001"
             with GraphDatabase.driver(uri, auth=self.auth_token, encrypted=False) as driver:
-                with driver.session(WRITE_ACCESS) as session:
+                with driver.session(access_mode=WRITE_ACCESS) as session:
                     with self.assertRaises(ClientError):
                         _ = session.run("CREATE (n {name:'Bob'})")
 
@@ -267,7 +267,7 @@ def test_forgets_address_on_forbidden_on_read_only_database_error(self):
         with StubCluster({9001: "router.script", 9006: "forbidden_on_read_only_database.script"}):
             uri = "bolt+routing://127.0.0.1:9001"
             with GraphDatabase.driver(uri, auth=self.auth_token, encrypted=False) as driver:
-                with driver.session(WRITE_ACCESS) as session:
+                with driver.session(access_mode=WRITE_ACCESS) as session:
                     with self.assertRaises(ClientError):
                         _ = session.run("CREATE (n {name:'Bob'})")
 
@@ -285,7 +285,7 @@ def test_forgets_address_on_service_unavailable_error(self):
         with StubCluster({9001: "router.script", 9004: "rude_reader.script"}):
             uri = "bolt+routing://127.0.0.1:9001"
             with GraphDatabase.driver(uri, auth=self.auth_token, encrypted=False) as driver:
-                with driver.session(READ_ACCESS) as session:
+                with driver.session(access_mode=READ_ACCESS) as session:
                     with self.assertRaises(SessionExpired):
                         _ = session.run("RETURN 1")
 
@@ -309,7 +309,7 @@ def test_forgets_address_on_database_unavailable_error(self):
         with StubCluster({9001: "router.script", 9004: "database_unavailable.script"}):
             uri = "bolt+routing://127.0.0.1:9001"
             with GraphDatabase.driver(uri, auth=self.auth_token, encrypted=False) as driver:
-                with driver.session(READ_ACCESS) as session:
+                with driver.session(access_mode=READ_ACCESS) as session:
                     with self.assertRaises(TransientError):
                         _ = session.run("RETURN 1")