Add has_database function and correct docstring of get_database (#341)

has_database is better to check for existance of a database
rather than using connect or catch the exception of get_database

Author: rrooij

terminusdb_client/client/Client.py

@@ -2799,10 +2799,12 @@ def get_database(self, dbid: str, team: Optional[str] = None) -> Optional[dict]:
         ------
         InterfaceError
             if the client does not connect to a server
+        DatabaseError
+            if the database can't be found
 
         Returns
         -------
-        dict or None if not found
+        dict
         """
         self._check_connection(check_db=False)
         team = team if team else self.team
@@ -2813,6 +2815,35 @@ def get_database(self, dbid: str, team: Optional[str] = None) -> Optional[dict]:
         )
         return json.loads(_finish_response(result))
 
+    def has_database(self, dbid: str, team: Optional[str] = None) -> bool:
+        """
+        Check whether a database exists
+
+        Parameters
+        ----------
+        dbid : str
+            The id of the database
+        team : str
+            The organization of the database (default self.team)
+
+        Raises
+        ------
+        InterfaceError
+            if the client does not connect to a server
+
+        Returns
+        -------
+        True or False if not found
+        """
+        self._check_connection(check_db=False)
+        team = team if team else self.team
+        r = requests.head(
+            f"{self.api}/db/{team}/{dbid}",
+            headers=self._default_headers,
+            auth=self._auth(),
+        )
+        return r.status_code == 200
+
     def get_databases(self) -> List[dict]:
         """
         Returns a list of database metadata records for all databases the user has access to

terminusdb_client/tests/integration_tests/test_client.py

@@ -175,6 +175,17 @@ def test_get_database(docker_url):
     assert db['name'] == db_name
     db_with_team = client.get_database(db_name, team='admin')
     assert db_with_team['name'] == db_name
+    with pytest.raises(DatabaseError):
+        client.get_database("DOES_NOT_EXISTDB")
+
+
+def test_has_database(docker_url):
+    client = Client(docker_url, user_agent=test_user_agent, team="admin")
+    client.connect()
+    db_name = "testDB" + str(random())
+    client.create_database(db_name, team="admin")
+    assert client.has_database(db_name)
+    assert not client.has_database("DOES_NOT_EXISTDB")
 
 
 def test_add_get_remove_user(docker_url):

terminusdb_client/tests/test_Client.py

@@ -181,6 +181,20 @@ def test_get_database(mocked_requests, mocked_requests2):
     )
 
 
+@mock.patch("requests.get", side_effect=mocked_request_success)
+@mock.patch("requests.head", side_effect=mocked_request_success)
+def test_has_database(mocked_requests, mocked_requests2):
+    client = Client("http://localhost:6363")
+    client.connect(user="admin", team="admin", key="root")
+    db_name = "testDB" + str(random.randrange(100000))
+    client.has_database(db_name)
+    requests.head.assert_called_with(
+        f"http://localhost:6363/api/db/admin/{db_name}",
+        auth=("admin", "root"),
+        headers={"user-agent": f"terminusdb-client-python/{__version__}"},
+    )
+
+
 @pytest.mark.skip(reason="temporary not avaliable")
 @mock.patch("requests.head", side_effect=mocked_request_success)
 @mock.patch("requests.get", side_effect=mocked_request_success)