df: types: Make DataFlow not a dataclass

* dataclasses.asdict recursively converts dataclasses into dicts.
  This resulted in the DataFlow.export method not being called and
  by_origin ending up in configs which had DataFlows as a property
  (dffml.dataflow.run). By making DataFlow a regular class and not a
  dataclass we avoid this issue.

Signed-off-by: John Andersen <[email protected]>

Author: pdxjohnny

CHANGELOG.md

@@ -14,6 +14,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Add python code for tensorflow DNNEstimator
 ### Fixed
 - New model tutorial mentions file paths that should be edited.
+- DataFlow is no longer a dataclass to prevent it from being exported
+  incorrectly.
 
 ## [0.3.5] - 2020-03-10
 ### Added

dffml/df/types.py

@@ -412,22 +412,33 @@ def _fromdict(cls, **kwargs):
         return cls(**kwargs)
 
 
-@dataclass
 class DataFlow:
-    operations: Dict[str, Union[Operation, Callable]]
-    seed: List[Input] = field(default=None)
-    configs: Dict[str, BaseConfig] = field(default=None)
-    definitions: Dict[str, Definition] = field(init=False)
-    flow: Dict[str, InputFlow] = field(default=None)
-    by_origin: Dict[Stage, Dict[str, Operation]] = field(default=None)
-    # Implementations can be provided in case they haven't been registered via
-    # the entrypoint system.
-    implementations: Dict[str, "OperationImplementation"] = field(default=None)
-    forward: Forward = field(default_factory=lambda: Forward())
+    def __init__(
+        self,
+        operations: Dict[str, Union[Operation, Callable]],
+        seed: List[Input] = None,
+        configs: Dict[str, BaseConfig] = None,
+        definitions: Dict[str, Definition] = False,
+        flow: Dict[str, InputFlow] = None,
+        by_origin: Dict[Stage, Dict[str, Operation]] = None,
+        # Implementations can be provided in case they haven't been registered
+        # via the entrypoint system.
+        implementations: Dict[str, "OperationImplementation"] = None,
+        forward: Forward = None,
+    ) -> None:
+        self.operations = operations
+        self.seed = seed
+        self.configs = configs
+        self.definitions = definitions
+        self.flow = flow
+        self.by_origin = by_origin
+        self.implementations = implementations
+        self.forward = forward
 
-    def __post_init__(self):
         # Prevent usage of a global dict (if we set default to {} then all the
         # instances will share the same instance of that dict, or list)
+        if self.forward is None:
+            self.forward = Forward()
         if self.seed is None:
             self.seed = []
         if self.configs is None: