python(refactor): update CSV import example (#585)

Author: wei-qlu

python/examples/data_import/csv/.env.example

@@ -0,0 +1,4 @@
+SIFT_GRPC_URI=
+SIFT_REST_URI=
+SIFT_API_KEY=
+ASSET_NAME=

python/examples/data_import/csv/custom/.env-example

@@ -0,0 +1,48 @@
+"""Import a CSV file into Sift."""
+
+import os
+
+from dotenv import load_dotenv
+from sift_client import SiftClient
+
+if __name__ == "__main__":
+    load_dotenv()
+
+    grpc_uri = os.getenv("SIFT_GRPC_URI")
+    assert grpc_uri, "expected 'SIFT_GRPC_URI' environment variable to be set"
+
+    rest_uri = os.getenv("SIFT_REST_URI")
+    assert rest_uri, "expected 'SIFT_REST_URI' environment variable to be set"
+
+    apikey = os.getenv("SIFT_API_KEY")
+    assert apikey, "expected 'SIFT_API_KEY' environment variable to be set"
+
+    asset_name = os.getenv("ASSET_NAME")
+    assert asset_name, "expected 'ASSET_NAME' environment variable to be set"
+
+    client = SiftClient(api_key=apikey, grpc_url=grpc_uri, rest_url=rest_uri)
+
+    # Auto-detect the config and import the file.
+    import_job = client.data_import.import_from_path(
+        "sample_data.csv",
+        asset=asset_name,
+    )
+
+    import_job.wait_until_complete()
+
+    # If auto-detect doesn't quite match your file, inspect the config and patch
+    # it before importing. Common fixes: override a column's data type, change
+    # the time column or format, or drop a column that shouldn't be imported.
+    #
+    # config = client.data_import.detect_config("sample_data.csv")
+    # print(config)  # inspect what was auto-detected
+    #
+    # # Example: drop a column from the import
+    # config.data_columns = [dc for dc in config.data_columns if dc.name != "channel_0"]
+    #
+    # import_job = client.data_import.import_from_path(
+    #     "sample_data.csv",
+    #     asset=asset_name,
+    #     config=config,
+    # )
+    # import_job.wait_until_complete()

python/examples/data_import/csv/custom/main.py

@@ -1,2 +1,2 @@
 python-dotenv
-sift-stack-py
+sift-stack-py