Merge branch 'peiwen/add_example_flow' of https://github.com/microsof…

…t/promptflow into peiwen/add_example_flow

src/promptflow/promptflow/contracts/run_mode.py

@@ -6,13 +6,22 @@
 
 
 class RunMode(str, Enum):
+    """An enumeration of possible run modes."""
+
     Test = "Test"
     SingleNode = "SingleNode"
     Batch = "Batch"
 
     @classmethod
     def parse(cls, value: str):
-        """Parse string to RunMode."""
+        """Parse a string to a RunMode enum value.
+
+        :param value: The string to parse.
+        :type value: str
+        :return: The corresponding RunMode enum value.
+        :rtype: ~promptflow.contracts.run_mode.RunMode
+        :raises ValueError: If the value is not a valid string.
+        """
         if not isinstance(value, str):
             raise ValueError(f"Invalid value type to parse: {type(value)}")
         if value == "SingleNode":

src/promptflow/promptflow/contracts/trace.py

@@ -8,13 +8,37 @@
 
 
 class TraceType(str, Enum):
+    """An enumeration class to represent different types of traces."""
+
     LLM = "LLM"
     TOOL = "Tool"
     LANGCHAIN = "LangChain"
 
 
 @dataclass
 class Trace:
+    """A dataclass that represents a trace of a program execution.
+
+    :param name: The name of the trace.
+    :type name: str
+    :param type: The type of the trace.
+    :type type: ~promptflow.contracts.trace.TraceType
+    :param inputs: The inputs of the trace.
+    :type inputs: Dict[str, Any]
+    :param output: The output of the trace, or None if not available.
+    :type output: Optional[Any]
+    :param start_time: The timestamp of the start time, or None if not available.
+    :type start_time: Optional[float]
+    :param end_time: The timestamp of the end time, or None if not available.
+    :type end_time: Optional[float]
+    :param error: The error message of the trace, or None if no error occurred.
+    :type error: Optional[str]
+    :param children: The list of child traces, or None if no children.
+    :type children: Optional[List[Trace]]
+    :param node_name: The node name of the trace, used for flow level trace, or None if not applicable.
+    :type node_name: Optional[str]
+    """
+
     name: str
     type: TraceType
     inputs: Dict[str, Any]