make argparse output nicer

dlt/cli/_dlt.py

@@ -1,6 +1,7 @@
 from typing import Any, Sequence, Type, cast, List, Dict
 import argparse
 import click
+import rich_argparse
 
 from dlt.version import __version__
 from dlt.common.runners import Venv
@@ -102,7 +103,6 @@ def __call__(
 def main() -> int:
     parser = argparse.ArgumentParser(
         description="Creates, adds, inspects and deploys dlt pipelines.",
-        formatter_class=argparse.ArgumentDefaultsHelpFormatter,
     )
     parser.add_argument(
         "--version", action="version", version="%(prog)s {version}".format(version=__version__)
@@ -146,6 +146,16 @@ def main() -> int:
         command.configure_parser(command_parser)
         installed_commands[command.command] = command
 
+    # recursively add formatter class
+    def add_formatter_class(parser: argparse.ArgumentParser) -> None:
+        parser.formatter_class = rich_argparse.RichHelpFormatter
+        for action in parser._actions:
+            if isinstance(action, argparse._SubParsersAction):
+                for _subcmd, subparser in action.choices.items():
+                    add_formatter_class(subparser)
+
+    add_formatter_class(parser)
+
     args = parser.parse_args()
 
     if Venv.is_virtual_env() and not Venv.is_venv_activated():

pyproject.toml

@@ -110,6 +110,7 @@ db-dtypes = { version = ">=1.2.0", optional = true }
 pyiceberg = { version = ">=0.8.1", optional = true }
 databricks-sdk = {version = ">=0.38.0", optional = true}
 pywin32 = {version = ">=306", optional = true, platform = "win32"}
+rich-argparse = "^1.6.0"
 
 [tool.poetry.extras]
 gcp = ["grpcio", "google-cloud-bigquery", "db-dtypes", "gcsfs"]