making orjson support optional

orjson can cause issues when compiling on Alpine Linux, and also on Read the Docs when building documentation.

Author: dantownsend

docs/src/piccolo/getting_started/installing_piccolo.rst

@@ -11,7 +11,6 @@ Pip
 
 Now install piccolo, ideally inside a `virtualenv <https://docs.python-guide.org/dev/virtualenvs/>`_:
 
-
 .. code-block:: python
 
     # Optional - creating a virtualenv on Unix:
@@ -21,3 +20,7 @@ Now install piccolo, ideally inside a `virtualenv <https://docs.python-guide.org
 
     # The important bit:
     pip install piccolo
+
+    # For optional orjson support, which improves JSON serialisation
+    # performance:
+    pip install piccolo[orjson]

docs/src/piccolo/query_types/select.rst

@@ -148,7 +148,10 @@ To return the data as a JSON string:
     >>> b.select().output(as_json=True).run_sync()
     '[{"name":"Pythonistas","manager":1,"popularity":1000,"id":1},{"name":"Rustaceans","manager":2,"popularity":500,"id":2}]'
 
-Piccolo uses `orjson <https://github.com/ijl/orjson>`_ for JSON serialisation, which is blazing fast, and can handle most Python types, including dates, datetimes, and UUIDs.
+Piccolo can use `orjson <https://github.com/ijl/orjson>`_ for JSON serialisation,
+which is blazing fast, and can handle most Python types, including dates,
+datetimes, and UUIDs. To install Piccolo with orjson support use
+`pip install piccolo[orjson]`.
 
 where
 ~~~~~

piccolo/query/base.py

@@ -5,7 +5,6 @@
 import typing as t
 
 from asyncpg.pgproto.pgproto import UUID
-import orjson as json
 
 from piccolo.querystring import QueryString
 from piccolo.utils.sync import run_sync
@@ -23,17 +22,6 @@ def __exit__(self, exception_type, exception, traceback):
         print(f"Duration: {self.end - self.start}s")
 
 
-def default(obj):
-    """
-    Used for handling edge cases which orjson can't serialise out of the box.
-    """
-    # This is the asyncpg UUID, not the builtin Python UUID, which orjon can
-    # serialise out of the box.
-    if isinstance(obj, (UUID, datetime.timedelta)):
-        return str(obj)
-    raise TypeError
-
-
 class Query:
 
     __slots__ = ("table",)
@@ -83,7 +71,14 @@ async def _process_results(self, results):
                     else:
                         raw = list(itertools.chain(*[j.values() for j in raw]))
                 if output._output.as_json:
-                    raw = json.dumps(raw, default=default)
+                    try:
+                        import orjson
+                    except ImportError:
+                        import json
+
+                        raw = json.dumps(raw, default=str)
+                    else:
+                        raw = orjson.dumps(raw, default=str).decode("utf8")
 
         return raw
 

requirements.txt

@@ -1,8 +1,7 @@
 aiosqlite==0.15.0
-asgiref==3.2.10
+asgiref==3.3.0
 asyncpg==0.21.0
 black==19.10b0
-colorama==0.4.3
-orjson==3.4.0
+colorama==0.4.4
 Jinja2==2.11.2
 targ==0.1.*

setup.py

@@ -42,6 +42,7 @@
         "piccolo": ["py.typed"],
     },
     install_requires=REQUIREMENTS,
+    extras_require={"orjson": ["orjson==3.4.1"]},
     license="MIT",
     classifiers=[
         "License :: OSI Approved :: MIT License",