* Adding support for sliceable boxes (thanks to Dias)

* Changing #215 support ruamel.yaml new syntax (thanks to Ivan Pepelnjak)

.gitignore

@@ -96,3 +96,4 @@ release.bat
 coverage/
 # don't upload cython files
 box/*.c
+.pytest_cache/

.pre-commit-config.yaml

@@ -38,7 +38,7 @@ repos:
   hooks:
     - id: cythonize-check
       name: Cythonize
-      entry: bash -c 'python setup.py build_ext --inplace'
+      entry: python setup.py build_ext --inplace
       language: system
       types: [python]
       pass_filenames: false

CHANGES.rst

@@ -5,7 +5,9 @@ Version 6.0.0
 -------------
 
 * Adding Cython support to greatly speed up normal Box operations on supported systems
+* Adding support for sliceable boxes (thanks to Dias)
 * Changing #208 __repr__ to produce `eval`-able text (thanks to Jeff Robbins)
+* Changing #215 support ruamel.yaml new syntax (thanks to Ivan Pepelnjak)
 * Changing `update` and `merge_update` to not use a keyword that could cause issues in rare circumstances
 * Fixing internal `_safe_key` logic to be twice as fast
 

box/box.py

@@ -501,6 +501,13 @@ def __getitem__(self, item, _ignore_default=False):
             if self._box_config["default_box"] and not _ignore_default:
                 return self.__get_default(item)
             raise BoxKeyError(str(err)) from _exception_cause(err)
+        except TypeError as err:
+            if isinstance(item, slice):
+                new_box = self._box_config["box_class"](**self.__box_config())
+                for x in list(super().keys())[item.start : item.stop : item.step]:
+                    new_box[x] = self[x]
+                return new_box
+            raise BoxTypeError(str(err)) from _exception_cause(err)
 
     def __getattr__(self, item):
         try:

box/converters.py

@@ -12,18 +12,24 @@
 
 from box.exceptions import BoxError
 
-yaml_available = True
+pyyaml_available = True
+ruamel_available = True
 toml_available = True
 msgpack_available = True
 
 try:
-    import ruamel.yaml as yaml
+    from ruamel.yaml import version_info, YAML
 except ImportError:
-    try:
-        import yaml  # type: ignore
-    except ImportError:
-        yaml = None  # type: ignore
-        yaml_available = False
+    ruamel_available = False
+else:
+    if version_info[1] < 17:
+        ruamel_available = False
+
+try:
+    import yaml
+except ImportError:
+    pyyaml_available = False
+
 try:
     import toml
 except ImportError:
@@ -36,6 +42,8 @@
     msgpack = None  # type: ignore
     msgpack_available = False
 
+yaml_available = pyyaml_available or ruamel_available
+
 BOX_PARAMETERS = (
     "default_box",
     "default_box_attr",
@@ -111,31 +119,64 @@ def _to_yaml(
     default_flow_style: bool = False,
     encoding: str = "utf-8",
     errors: str = "strict",
+    ruamel_typ: str = "rt",
     **yaml_kwargs,
 ):
     if filename:
         _exists(filename, create=True)
         with open(filename, "w", encoding=encoding, errors=errors) as f:
-            yaml.dump(obj, stream=f, default_flow_style=default_flow_style, **yaml_kwargs)
+            if ruamel_available:
+                yaml_dumper = YAML(typ=ruamel_typ)
+                yaml_dumper.default_flow_style = default_flow_style
+                return yaml_dumper.dump(obj, stream=f, **yaml_kwargs)
+            elif pyyaml_available:
+                return yaml.dump(obj, stream=f, default_flow_style=default_flow_style, **yaml_kwargs)
+            else:
+                raise BoxError("No YAML Parser available, please install ruamel.yaml>0.17 or PyYAML")
+
     else:
-        return yaml.dump(obj, default_flow_style=default_flow_style, **yaml_kwargs)
+        if ruamel_available:
+            yaml_dumper = YAML(typ=ruamel_typ)
+            yaml_dumper.default_flow_style = default_flow_style
+            with StringIO() as string_stream:
+                yaml_dumper.dump(obj, stream=string_stream, **yaml_kwargs)
+                return string_stream.getvalue()
+        elif pyyaml_available:
+            return yaml.dump(obj, default_flow_style=default_flow_style, **yaml_kwargs)
+        else:
+            raise BoxError("No YAML Parser available, please install ruamel.yaml>0.15 or PyYAML")
 
 
 def _from_yaml(
     yaml_string: str = None,
     filename: Union[str, PathLike] = None,
     encoding: str = "utf-8",
     errors: str = "strict",
+    ruamel_typ: str = "rt",
     **kwargs,
 ):
-    if "Loader" not in kwargs:
-        kwargs["Loader"] = yaml.SafeLoader
     if filename:
         _exists(filename)
         with open(filename, "r", encoding=encoding, errors=errors) as f:
-            data = yaml.load(f, **kwargs)
+            if ruamel_available:
+                yaml_loader = YAML(typ=ruamel_typ)
+                data = yaml_loader.load(stream=f)
+            elif pyyaml_available:
+                if "Loader" not in kwargs:
+                    kwargs["Loader"] = yaml.SafeLoader
+                data = yaml.load(f, **kwargs)
+            else:
+                raise BoxError("No YAML Parser available, please install ruamel.yaml>0.15 or PyYAML")
     elif yaml_string:
-        data = yaml.load(yaml_string, **kwargs)
+        if ruamel_available:
+            yaml_loader = YAML(typ=ruamel_typ)
+            data = yaml_loader.load(stream=yaml_string)
+        elif pyyaml_available:
+            if "Loader" not in kwargs:
+                kwargs["Loader"] = yaml.SafeLoader
+            data = yaml.load(yaml_string, **kwargs)
+        else:
+            raise BoxError("No YAML Parser available, please install ruamel.yaml>0.17 or PyYAML")
     else:
         raise BoxError("from_yaml requires a string or filename")
     return data

box/converters.pyi

@@ -25,13 +25,15 @@ def _to_yaml(
     default_flow_style: bool = False,
     encoding: str = "utf-8",
     errors: str = "strict",
+    ruamel_typ: str = "rt",
     **yaml_kwargs,
 ) -> Any: ...
 def _from_yaml(
     yaml_string: str = None,
     filename: Union[str, PathLike] = None,
     encoding: str = "utf-8",
     errors: str = "strict",
+    ruamel_typ: str = "rt",
     **kwargs,
 ) -> Any: ...
 def _to_toml(obj, filename: Union[str, PathLike] = None, encoding: str = "utf-8", errors: str = "strict") -> Any: ...

requirements-test.txt

@@ -4,5 +4,6 @@ pytest>=5.4.1
 pytest-cov>=2.8.1
 ruamel.yaml>=0.16,<0.17
 toml>=0.10.2
+types-PyYAML>=6.0.3
 types-toml>=0.1.3
 wheel>=0.34.2

requirements.txt

@@ -1,3 +1,3 @@
 msgpack>=1.0.0
-ruamel.yaml>=0.16.10,<0.17
+ruamel.yaml>=0.15
 toml>=0.10.2

test/test_box.py

@@ -9,6 +9,7 @@
 import shutil
 from multiprocessing import Queue
 from pathlib import Path
+from io import StringIO
 from test.common import (
     data_json_file,
     data_yaml_file,
@@ -23,7 +24,7 @@
 )
 
 import pytest
-import ruamel.yaml as yaml
+from ruamel.yaml import YAML
 
 from box import Box, BoxError, BoxKeyError, BoxList, ConfigBox, SBox, box
 from box.box import _get_dot_paths  # type: ignore
@@ -208,13 +209,17 @@ def test_to_json_basic(self):
 
     def test_to_yaml_basic(self):
         a = Box(test_dict)
-        assert yaml.load(a.to_yaml(), Loader=yaml.SafeLoader) == test_dict
+        yaml = YAML(typ="safe")
+        print("HERE")
+        print(a.to_yaml())
+        assert yaml.load(a.to_yaml()) == test_dict
 
     def test_to_yaml_file(self):
         a = Box(test_dict)
         a.to_yaml(tmp_yaml_file)
         with open(tmp_yaml_file) as f:
-            data = yaml.load(f, Loader=yaml.SafeLoader)
+            yaml = YAML(typ="safe")
+            data = yaml.load(f)
             assert data == test_dict
 
     def test_dir(self):
@@ -347,7 +352,11 @@ def test_from_json(self):
         assert bx.key1 == "value1"
 
     def test_from_yaml(self):
-        bx = Box.from_yaml(yaml.dump(test_dict), conversion_box=False, default_box=True)
+        yaml = YAML(typ="safe")
+        with StringIO() as sio:
+            yaml.dump(test_dict, sio)
+            data = sio.getvalue()
+        bx = Box.from_yaml(data, conversion_box=False, default_box=True)
         assert isinstance(bx, Box)
         assert bx.key1 == "value1"
         assert bx.Key_2 == Box()
@@ -1281,3 +1290,7 @@ def test_setdefault_dots_default(self):
         assert box.d.e["f.g"] == True
         assert isinstance(box["e.f"], BoxList)
         assert box.e.f[1] == 2
+
+    def test_box_slice(self):
+        data = Box(qwe=123, asd=234, q=1)
+        assert data[:-1] == Box(qwe=123, asd=234)