0.1.3 Orchestration: cron and airflow

local-data-platform/local_data_platform/cron_flow.py

@@ -0,0 +1,75 @@
+def cron_flow(cron_expression: str, etl_function: callable, *args, **kwargs) -> None:
+    """
+    Schedule an ETL (Extract, Transform, Load) process to run at specific intervals using a cron job.
+
+    Args:
+        cron_expression (str): The cron expression that specifies the schedule for the ETL job. It follows the standard 
+            cron format: "minute hour day_of_month month day_of_week".
+            Example: "0 2 * * *" for running the ETL job daily at 2 AM.
+        etl_function (callable): The function that executes the ETL process, which can be passed as a reference.
+            This function should handle the extract, transform, and load stages of the process.
+        *args: Additional positional arguments to pass to the ETL function.
+        **kwargs: Additional keyword arguments to pass to the ETL function.
+
+    Returns:
+        None
+
+    Raises:
+        ValueError: If the cron expression is invalid or if the ETL function is not callable.
+        Exception: If an error occurs during the scheduling or execution of the ETL job.
+
+    Example:
+        cron_flow("0 0 * * 0", run_etl_process, source="data_source", target="data_target")
+
+    Notes:
+        - This function requires the cron job to be set up and managed using a task scheduler (e.g., cron in Unix-like 
+          systems or any equivalent scheduling tool).
+        - Ensure that the ETL function handles any errors internally, as the scheduling system may not handle exceptions
+          r
+    """
+    print("I Orchestrate!")
+
+
+
+
+def run_etl_process(source: str, target: str, transform_function: callable = None, *args, **kwargs) -> None:
+    """
+    Execute the ETL (Extract, Transform, Load) process.
+
+    This function orchestrates the three stages of an ETL process:
+    1. Extract data from a source.
+    2. Optionally transform the data using a transformation function.
+    3. Load the transformed (or raw) data into the target destination.
+
+    Args:
+        source (str): The data source from which to extract the data. It can be a file path, database connection string,
+            or API endpoint.
+        target (str): The destination where the data will be loaded. It can be a database, file path, or another storage
+            mechanism.
+        transform_function (callable, optional): A function that performs the transformation of the extracted data. 
+            This function should accept the extracted data as input and return the transformed data. If no transformation 
+            is needed, this argument can be left as `None` (default is `None`).
+        *args: Additional positional arguments to pass to the transformation function or loading process.
+        **kwargs: Additional keyword arguments to pass to the transformation function or loading process.
+
+    Returns:
+        None
+
+    Raises:
+        ValueError: If the source or target is invalid or if the transformation function does not return the expected output.
+        IOError: If an error occurs during data extraction or loading.
+        Exception: For any other issues that occur during the ETL process.
+
+    Example:
+        run_etl_process(source="database_connection_string", 
+                        target="data_warehouse",
+                        transform_function=transform_data,
+                        batch_size=1000)
+
+    Notes:
+        - The `transform_function` is optional. If provided, it should handle the logic for transforming the extracted data.
+        - This function assumes that the source and target formats are compatible with the extraction and loading logic
+          implemented in the ETL process.
+        - The actual implementation of extraction, transformation, and loading will depend on the specific needs of the
+          application (e.g., connecting to databases, reading/writing files, etc.).
+    """