Merge pull request #10 from builder555/master

fetch only specific keys from all data

pysondb/db.py

@@ -99,7 +99,7 @@ def add(self, data: object) -> str:
             keys = db_data['keys']
             if not isinstance(keys, list):
                 raise SchemaTypeError(
-                    f"keys must of type 'list' and not {type(keys)}")
+                    f"keys must be of type 'list' and not {type(keys)}")
             if len(keys) == 0:
                 db_data['keys'] = sorted(list(data.keys()))
             else:
@@ -164,6 +164,23 @@ def add_many(self, data: object, json_response: bool = False) -> Union[SingleDat
 
         return new_data if json_response else None
 
+    def get_all_select_keys(self, keys: List[str]) -> ReturnWithIdType:
+        with self.lock:
+            file_data = self._load_file()
+            data = file_data['data']
+            existing_keys = file_data['keys']
+            if not isinstance(existing_keys, list):
+                raise SchemaTypeError(
+                    f"keys must be of type 'list' and not {type(existing_keys)}")
+            if not set(keys).issubset(existing_keys):
+                raise UnknownKeyError(
+                    f'Unrecognized key(s) {set(keys) ^ set(existing_keys)}'
+                    '(Unable to find the key(s) in the DB)'
+                )
+            if isinstance(data, dict):
+                return {k: {i: v[i] for i in keys} for k, v in data.items()}
+        return {}
+
     def get_all(self) -> ReturnWithIdType:
         with self.lock:
             data = self._load_file()['data']

setup.cfg

@@ -1,6 +1,6 @@
 [metadata]
 name = pysondb-v2
-version = 2.1.0
+version = 2.2.0
 author = Adwaith Rajesh
 author_email = adwaithrajesh3180@gmail.com
 description = A Simple, Lightweight, Efficent JSON based database for Python.

tests/test_db_get_all_select_keys.py

@@ -0,0 +1,63 @@
+import json
+import pytest
+from pysondb.db import PysonDB
+from pysondb.errors import UnknownKeyError
+
+
+TEST_DATA = {
+    'version': 2,
+    'keys': ['age', 'name', 'toy'],
+    'data': {
+        '2352346': {
+            'age': 4,
+            'name': 'mathew_first',
+            'toy': 'car',
+        },
+        '1234567': {
+            'age': 9,
+            'name': 'new_user',
+            'toy': 'ball',
+        }
+    }
+}
+
+
+def test_get_all_select_keys(tmpdir):
+    f = tmpdir.join('test.json')
+    f.write(json.dumps(TEST_DATA))
+
+    db = PysonDB(f.strpath)
+    assert db.get_all_select_keys(['age']) == {
+        '2352346': {
+            'age': 4,
+        },
+        '1234567': {
+            'age': 9,
+        }
+    }
+    assert db.get_all_select_keys(['name', 'toy']) == {
+        '2352346': {
+            'name': 'mathew_first',
+            'toy': 'car',
+        },
+        '1234567': {
+            'name': 'new_user',
+            'toy': 'ball',
+        }
+    }
+
+
+def test_get_all_select_keys_empty_file(tmpdir):
+    f = tmpdir.join('test.json')
+    f.write(json.dumps({'version': 2, 'keys': [], 'data': {}}))
+
+    db = PysonDB(f.strpath)
+    assert db.get_all_select_keys([]) == {}
+
+def test_get_all_select_keys_wrong_key(tmpdir):
+    f = tmpdir.join('test.json')
+    f.write(json.dumps(TEST_DATA))
+
+    db = PysonDB(f.strpath)
+    with pytest.raises(UnknownKeyError):
+        db.get_all_select_keys(['wrong_key'])