fix pipeline schema cli command

dlt/cli/_dlt.py

@@ -498,7 +498,10 @@ def main() -> int:
     )
     pipe_cmd_schema = pipeline_subparsers.add_parser("schema", help="Displays default schema")
     pipe_cmd_schema.add_argument(
-        "--format", choices=["json", "yaml"], default="yaml", help="Display schema in this format"
+        "--format",
+        choices=["json", "yaml"],
+        default="yaml",
+        help="Display schema in this format",
     )
     pipe_cmd_schema.add_argument(
         "--remove-defaults", action="store_true", help="Does not show default hint values"

dlt/cli/pipeline_command.py

@@ -263,7 +263,12 @@ def _display_pending_packages() -> Tuple[Sequence[str], Sequence[str]]:
             fmt.warning("Pipeline does not have a default schema")
         else:
             fmt.echo("Found schema with name %s" % fmt.bold(p.default_schema_name))
-        schema_str = p.default_schema.to_pretty_yaml(remove_defaults=True)
+        format = command_kwargs.get("format")
+        s = p.default_schema
+        if format == "json":
+            schema_str = json.dumps(s.to_dict(remove_defaults=remove_defaults), pretty=True)
+        else:
+            schema_str = s.to_pretty_yaml(remove_defaults=remove_defaults)
         fmt.echo(schema_str)
 
     if operation == "drop":

docs/website/docs/intro-snippets.py

@@ -18,14 +18,13 @@ def intro_snippet() -> None:
         response.raise_for_status()
         data.append(response.json())
     # Extract, normalize, and load the data
-    load_info = pipeline.run(data, table_name='player')
+    load_info = pipeline.run(data, table_name="player")
     # @@@DLT_SNIPPET_END api
 
     assert_load_info(load_info)
 
 
 def csv_snippet() -> None:
-
     # @@@DLT_SNIPPET_START csv
     import dlt
     import pandas as pd
@@ -50,8 +49,8 @@ def csv_snippet() -> None:
 
     assert_load_info(load_info)
 
-def db_snippet() -> None:
 
+def db_snippet() -> None:
     # @@@DLT_SNIPPET_START db
     import dlt
     from sqlalchemy import create_engine
@@ -74,13 +73,9 @@ def db_snippet() -> None:
         )
 
         # Convert the rows into dictionaries on the fly with a map function
-        load_info = pipeline.run(
-            map(lambda row: dict(row._mapping), rows),
-            table_name="genome"
-        )
+        load_info = pipeline.run(map(lambda row: dict(row._mapping), rows), table_name="genome")
 
     print(load_info)
     # @@@DLT_SNIPPET_END db
 
     assert_load_info(load_info)
-