add datetime support (#32)

#minor adding datetime support

CHANGELOG.md

@@ -9,6 +9,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
+- datetime parsing
+
 ### Changed
 
 ### Fixed

README.md

@@ -30,13 +30,15 @@ import os
 from dataclasses import dataclass, field
 from typing import List, Dict, Text, Union
 from dateutil.relativedelta import relativedelta
+from datetime import datetime
 import dataconf
 
 conf = """
 str_name = test
 str_name = ${?HOME}
 dash-to-underscore = true
 float_num = 2.2
+iso_datetime = "2000-01-01T20:00:00"
 # this is a comment
 list_data = [
     a
@@ -83,6 +85,7 @@ class Config:
     str_name: Text
     dash_to_underscore: bool
     float_num: float
+    iso_datetime: datetime
     list_data: List[Text]
     nested: Nested
     nested_list: List[Nested]

confs/readme.hocon

@@ -2,6 +2,7 @@ str_name = test
 str_name = ${?HOME}
 dash-to-underscore = true
 float_num = 2.2
+iso_datetime = "2000-01-01T20:00:00"
 # this is a comment
 list_data = [
     a

dataconf/exceptions.py

@@ -1,22 +1,34 @@
 class TypeConfigException(Exception):
+    """Type mismatch exception."""
+
     pass
 
 
 class MissingTypeException(Exception):
+    """Missing type exception (e.g. List instead of List[int]."""
+
     pass
 
 
 class MalformedConfigException(Exception):
+    """Missing values exception."""
+
     pass
 
 
 class UnexpectedKeysException(Exception):
+    """Unexpected keys exception."""
+
     pass
 
 
 class EnvListOrderException(Exception):
+    """Ordering exception."""
+
     pass
 
 
-class EnvParseException(Exception):
+class ParseException(Exception):
+    """Parsing exception."""
+
     pass

dataconf/utils.py

@@ -2,16 +2,18 @@
 from dataclasses import asdict
 from dataclasses import fields
 from dataclasses import is_dataclass
+from datetime import datetime
 from typing import get_args
 from typing import get_origin
 from typing import Union
 
 from dataconf.exceptions import EnvListOrderException
-from dataconf.exceptions import EnvParseException
 from dataconf.exceptions import MalformedConfigException
 from dataconf.exceptions import MissingTypeException
+from dataconf.exceptions import ParseException
 from dataconf.exceptions import TypeConfigException
 from dataconf.exceptions import UnexpectedKeysException
+from dateutil.parser import isoparse
 from dateutil.relativedelta import relativedelta
 from pyhocon import ConfigFactory
 from pyhocon.config_tree import ConfigList
@@ -136,6 +138,15 @@ def __parse(value: any, clazz, path):
     if clazz is str:
         return __parse_type(value, clazz, path, isinstance(value, str))
 
+    if clazz is datetime:
+        dt = __parse_type(value, clazz, path, isinstance(value, str))
+        try:
+            return isoparse(dt)
+        except ValueError as e:
+            raise ParseException(
+                f"expected type {clazz} at {path}, cannot parse due to {e}"
+            )
+
     if clazz is relativedelta:
         return __parse_type(value, clazz, path, isinstance(value, relativedelta))
 
@@ -251,8 +262,8 @@ def int_or_string(v):
                 try:
                     v = ConfigFactory.parse_string(v)
                 except pyparsing.ParseBaseException as e:
-                    raise EnvParseException(
-                        f"env var {k} ends with `_` and expects a nested config, but got: {e}"
+                    raise ParseException(
+                        f"env var {k} ends with `_` and expects a nested config, got: {e}"
                     )
                 k = k[:-1]
 

tests/test_dict_list_parsing.py

@@ -1,5 +1,5 @@
 from dataconf.exceptions import EnvListOrderException
-from dataconf.exceptions import EnvParseException
+from dataconf.exceptions import ParseException
 from dataconf.utils import __dict_list_parsing as dict_list_parsing
 import pytest
 
@@ -82,5 +82,5 @@ def test_bad_nested_config(self) -> None:
         env = {
             "P_A_0_": "::",
         }
-        with pytest.raises(EnvParseException):
+        with pytest.raises(ParseException):
             dict_list_parsing("P", env)

tests/test_parse.py

@@ -1,5 +1,7 @@
 from dataclasses import dataclass
 from dataclasses import field
+from datetime import datetime
+from datetime import timezone
 import os
 from typing import Dict
 from typing import List
@@ -11,6 +13,7 @@
 from dataconf import loads
 from dataconf.exceptions import MalformedConfigException
 from dataconf.exceptions import MissingTypeException
+from dataconf.exceptions import ParseException
 from dataconf.exceptions import TypeConfigException
 from dataconf.exceptions import UnexpectedKeysException
 from dateutil.relativedelta import relativedelta
@@ -154,6 +157,29 @@ class A:
         """
         assert loads(conf, A) == A(b="test")
 
+    def test_datetime(self) -> None:
+        @dataclass
+        class A:
+            b: datetime
+
+        conf = """
+        b = "1997-07-16T19:20:07+01:00"
+        """
+        assert loads(conf, A) == A(
+            b=datetime(1997, 7, 16, 18, 20, 7, tzinfo=timezone.utc)
+        )
+
+    def test_bad_datetime(self) -> None:
+        @dataclass
+        class A:
+            b: datetime
+
+        conf = """
+        b = "1997-07-16 19:20:0701:00"
+        """
+        with pytest.raises(ParseException):
+            assert loads(conf, A)
+
     def test_optional_with_default(self) -> None:
         @dataclass
         class A:

tests/test_regression.py

@@ -1,6 +1,7 @@
 from abc import ABCMeta
 from dataclasses import dataclass
 from dataclasses import field
+from datetime import datetime
 import os
 from typing import Dict
 from typing import List
@@ -39,6 +40,7 @@ class Config:
             str_name: Text
             dash_to_underscore: bool
             float_num: float
+            iso_datetime: datetime
             list_data: List[Text]
             nested: Nested
             nested_list: List[Nested]
@@ -56,6 +58,7 @@ class Config:
             str_name=os.environ.get("HOME", "test"),
             dash_to_underscore=True,
             float_num=2.2,
+            iso_datetime=datetime(2000, 1, 1, 20),
             list_data=["a", "b"],
             nested=Nested(a="test", b=1),
             nested_list=[Nested(a="test1", b=2.5)],