feat: add default encoder for Pattern type

closes #2045
pydantic · Oct 27, 2020 · fdd0365 · fdd0365
1 parent 95435de
commit fdd0365
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diff --git a/changes/2045-PrettyWood.md b/changes/2045-PrettyWood.md
@@ -0,0 +1 @@
+add default encoder for `Pattern` type
diff --git a/pydantic/json.py b/pydantic/json.py
@@ -46,6 +46,7 @@ def isoformat(o: Union[datetime.date, datetime.time]) -> str:
 
 def pydantic_encoder(obj: Any) -> Any:
     from dataclasses import asdict, is_dataclass
+    from re import Pattern
 
     from .main import BaseModel
 
@@ -54,6 +55,9 @@ def pydantic_encoder(obj: Any) -> Any:
     elif is_dataclass(obj):
         return asdict(obj)
 
+    if isinstance(obj, Pattern):
+        return obj.pattern
+
     # Check the class type and its superclasses for a matching encoder
     for base in obj.__class__.__mro__[:-1]:
         try:

diff --git a/tests/test_json.py b/tests/test_json.py
@@ -1,5 +1,6 @@
 import datetime
 import json
+import re
 import sys
 from dataclasses import dataclass as vanilla_dataclass
 from decimal import Decimal
@@ -51,6 +52,7 @@ class MyEnum(Enum):
         (Decimal('12.34'), '12.34'),
         (create_model('BarModel', a='b', c='d')(), '{"a": "b", "c": "d"}'),
         (MyEnum.foo, '"bar"'),
+        (re.compile('^regex$'), '"^regex$"'),
     ],
 )
 def test_encoding(input, output):