cleaning up preconf and builtin serializers

3 files changed, 64 insertions, 46 deletions

diff --git a/Pipfile b/Pipfile
index b9ba84f..71e4f7c 100644
--- a/Pipfile
+++ b/Pipfile
@@ -8,4 +8,4 @@ name = "pypi"
 [dev-packages]
 
 [requires]
-python_version = "3.7"
+python_version = "3.9"
diff --git a/requests_cache/serializers/__init__.py b/requests_cache/serializers/__init__.py
index 8078656..a4049cb 100644
--- a/requests_cache/serializers/__init__.py
+++ b/requests_cache/serializers/__init__.py
@@ -1,31 +1,40 @@
 import pickle
 
-from itsdangerous import Signer
-
 from .. import get_placeholder_class
+from . import preconf
 from .pipeline import SerializerPipeline, Stage
 
 pickle_serializer = pickle
 
+try:
+    from itsdangerous import Signer
 
-def safe_pickle_serializer(secret_key=None, salt="requests-cache", **kwargs):
-    if not secret_key:
-        raise ValueError("Cannot use itsdangerous without a secret key!")
-    return SerializerPipeline(
-        [
-            pickle_serializer,
-            Stage(Signer(secret_key=secret_key, salt=salt), dumps='sign', loads='unsign'),
-        ],
-    )
+    def safe_pickle_serializer(secret_key=None, salt="requests-cache", **kwargs):
+        if not secret_key:
+            raise ValueError("Cannot use itsdangerous without a secret key!")
+        return SerializerPipeline(
+            [
+                pickle_serializer,
+                Stage(Signer(secret_key=secret_key, salt=salt), dumps='sign', loads='unsign'),
+            ],
+        )
+
+
+except ImportError as e:
+    safe_pickle_serializer = get_placeholder_class(e)
 
 
 try:
-    from . import preconf
+    import ujson as json
 
-    try:
-        import ujson as json
-    except ImportError:
-        import json
+    json_serializer = SerializerPipeline(
+        [
+            preconf.ujson_converter,  # CachedResponse -> JSON
+            json,  # JSON -> str
+        ],
+    )
+except ImportError:
+    import json
 
     json_serializer = SerializerPipeline(
         [
@@ -34,25 +43,32 @@ try:
         ],
     )
 
-    try:
-        import bson.json_util
-
-        bson_serializer = SerializerPipeline(
-            [
-                preconf.bson_converter,  # CachedResponse -> BSON
-                bson.json_util,  # BSON -> str
-            ],
-        )
-    except ImportError as e:
-        bson_serializer = get_placeholder_class(e)
+try:
+    import bson.json_util
 
+    bson_serializer = SerializerPipeline(
+        [
+            preconf.bson_converter,  # CachedResponse -> BSON
+            bson.json_util,  # BSON -> str
+        ],
+    )
 except ImportError as e:
-    json_serializer = get_placeholder_class(e)
     bson_serializer = get_placeholder_class(e)
 
+try:
+    import pyyaml
+
+    yaml_serializer = SerializerPipeline(
+        [preconf.pyyaml_converter, Stage(pyyaml, loads='load', dumps='dump')]
+    )
+except ImportError as e:
+    yaml_serializer = get_placeholder_class(e)
+
+
 SERIALIZERS = {
     "pickle": pickle_serializer,
     "safe_pickle": safe_pickle_serializer,
     "json": json_serializer,
     "bson": bson_serializer,
+    "yaml": yaml_serializer,
 }
diff --git a/requests_cache/serializers/preconf.py b/requests_cache/serializers/preconf.py
index 17f4056..acd63f1 100644
--- a/requests_cache/serializers/preconf.py
+++ b/requests_cache/serializers/preconf.py
@@ -1,20 +1,17 @@
 import datetime
-import importlib
-import pkgutil
 from functools import partial
-from pathlib import Path
 
 from requests.cookies import RequestsCookieJar, cookiejar_from_dict
 from requests.structures import CaseInsensitiveDict
 from urllib3.response import HTTPHeaderDict
 
+from .. import get_placeholder_class
 from ..models import CachedResponse
 from .pipeline import Stage
 
 try:
-    from typing import ForwardRef
-
-    from cattr import GenConverter, preconf
+    from cattr import GenConverter
+    from cattr.preconf import bson, json, msgpack, orjson, pyyaml, tomlkit, ujson
 
     def to_datetime(obj, cls) -> datetime:
         if isinstance(obj, str):
@@ -56,21 +53,26 @@ try:
         converter.register_structure_hook(HTTPHeaderDict, lambda obj, cls: HTTPHeaderDict(obj))
 
         converter.register_structure_hook(
-            ForwardRef('CachedResponse'),
+            CachedResponse,
             lambda obj, cls: converter.structure(obj, CachedResponse),
         )
         converter = CattrsStage(converter, dumps='unstructure', loads='structure')
 
         return converter
 
-    preconf_module_names = list(
-        m.name for m in pkgutil.iter_modules((str(Path(preconf.__file__).parent),))
-    )
+    bson_converter = init_converter(bson.make_converter)
+    json_converter = init_converter(json.make_converter)
+    msgpack_converter = init_converter(msgpack.make_converter)
+    orjson_converter = init_converter(orjson.make_converter)
+    pyyaml_converter = init_converter(pyyaml.make_converter)
+    tomlkit_converter = init_converter(tomlkit.make_converter)
+    ujson_converter = init_converter(ujson.make_converter)
 
-    GLOBALS = globals()
-    for preconf_module_name in preconf_module_names:
-        preconf_module = importlib.import_module(f"cattr.preconf.{preconf_module_name}")
-        converter = preconf_module.make_converter
-        GLOBALS[f"{preconf_module_name}_converter"] = init_converter(preconf_module.make_converter)
-except ImportError:
-    pass
+except ImportError as e:
+    bson_converter = get_placeholder_class(e)
+    json_converter = get_placeholder_class(e)
+    msgpack_converter = get_placeholder_class(e)
+    orjson_converter = get_placeholder_class(e)
+    pyyaml_converter = get_placeholder_class(e)
+    tomlkit_converter = init_converter(tomlkit.make_converter)
+    ujson_converter = get_placeholder_class(e)