Add dictionary key lookup utility

Author: Conengmo

folium/utilities.py

@@ -490,3 +490,20 @@ def parse_options(**kwargs):
     return {camelize(key): value
             for key, value in kwargs.items()
             if value is not None}
+
+
+def dict_get(d, *keys):
+    """Return the field in dictionary d under the given keys.
+
+    Examples
+    --------
+    >>> dict_get({'hi': {'there': 42}}, 'hi', 'there')
+    42
+
+    """
+    if len(keys) == 0:
+        return d
+    if not isinstance(d, dict):
+        raise TypeError('The first argument should be a dictionary, not a {}.'
+                        .format(type(d)))
+    return dict_get(d[keys[0]], *keys[1:])

tests/test_utilities.py

@@ -11,6 +11,7 @@
     deep_copy,
     get_obj_in_upper_tree,
     parse_options,
+    dict_get,
 )
 
 
@@ -154,3 +155,16 @@ def test_parse_options():
     assert parse_options(thing=None) == {}
     assert parse_options(long_thing=42) == {'longThing': 42}
     assert parse_options(thing=42, lst=[1, 2]) == {'thing': 42, 'lst': [1, 2]}
+
+
+def test_dict_get():
+    assert dict_get({}) == {}
+    assert dict_get({'hi': 'there'}) == {'hi': 'there'}
+    assert dict_get({'hi': {'there': 42}}, 'hi', 'there') == 42
+    assert dict_get({'hi': [1, 2, 3]}, 'hi') == [1, 2, 3]
+    with pytest.raises(TypeError):
+        dict_get({'hi': 42}, 'hi', 'wrong-key')
+    with pytest.raises(TypeError):
+        dict_get(42, 'wrong-key')
+    with pytest.raises(KeyError):
+        dict_get({'hi': 42}, 'wrong-key')