Added Rich-based pretty print method. (#1617)

Author: kmvanbrunt

CHANGELOG.md

@@ -79,6 +79,7 @@ prompt is displayed.
         - **pre_prompt**: hook method that is called before the prompt is displayed, but after
           `prompt-toolkit` event loop has started
         - **read_secret**: read secrets like passwords without displaying them to the terminal
+        - **ppretty**: a cmd2-compatible replacement for `rich.pretty.pprint()`
     - New settables:
         - **max_column_completion_results**: (int) the maximum number of completion results to
           display in a single column

cmd2/cmd2.py

@@ -88,6 +88,7 @@
     RenderableType,
 )
 from rich.highlighter import ReprHighlighter
+from rich.pretty import Pretty
 from rich.rule import Rule
 from rich.style import (
     Style,
@@ -1822,6 +1823,56 @@ def ppaged(
                 rich_print_kwargs=rich_print_kwargs,
             )
 
+    def ppretty(
+        self,
+        obj: Any,
+        *,
+        file: IO[str] | None = None,
+        indent_size: int = 4,
+        indent_guides: bool = True,
+        max_length: int | None = None,
+        max_string: int | None = None,
+        max_depth: int | None = None,
+        expand_all: bool = False,
+        end: str = "\n",
+    ) -> None:
+        """Pretty print an object.
+
+        This is a cmd2-compatible replacement for rich.pretty.pprint().
+
+        :param obj: object to pretty print
+        :param file: file stream being written to or None for self.stdout.
+                     Defaults to None.
+        :param indent_size: number of spaces in indent. Defaults to 4.
+        :param indent_guides: enable indentation guides. Defaults to True.
+        :param max_length: maximum length of containers before abbreviating, or None for no abbreviation.
+                           Defaults to None.
+        :param max_string: maximum length of strings before truncating, or None to disable. Defaults to None.
+        :param max_depth: maximum depth for nested data structures, or None for unlimited depth. Defaults to None.
+        :param expand_all: Expand all containers. Defaults to False.
+        :param end: string to write at end of printed text. Defaults to a newline.
+        """
+        # The overflow and soft_wrap values match those in rich.pretty.pprint().
+        # This ensures long strings are neither truncated with ellipses nor broken
+        # up by injected newlines.
+        pretty_obj = Pretty(
+            obj,
+            indent_size=indent_size,
+            indent_guides=indent_guides,
+            max_length=max_length,
+            max_string=max_string,
+            max_depth=max_depth,
+            expand_all=expand_all,
+            overflow="ignore",
+        )
+
+        self.print_to(
+            file or self.stdout,
+            pretty_obj,
+            soft_wrap=True,
+            end=end,
+        )
+
     def get_bottom_toolbar(self) -> list[str | tuple[str, str]] | None:
         """Get the bottom toolbar content.
 

examples/pretty_print.py

@@ -1,42 +1,26 @@
 #!/usr/bin/env python3
-"""A simple example demonstrating how to pretty print JSON data in a cmd2 app using rich."""
-
-from rich.json import JSON
+"""A simple example demonstrating how to pretty print data."""
 
 import cmd2
 
 EXAMPLE_DATA = {
     "name": "John Doe",
     "age": 30,
     "address": {"street": "123 Main St", "city": "Anytown", "state": "CA"},
-    "hobbies": ["reading", "hiking", "coding"],
+    "hobbies": ["reading", "hiking", "coding", "cooking", "running", "painting", "music", "photography", "cycling"],
+    "member": True,
+    "vip": False,
+    "phone": None,
 }
 
 
 class Cmd2App(cmd2.Cmd):
     def __init__(self) -> None:
         super().__init__()
-        self.data = EXAMPLE_DATA
-
-    def do_normal(self, _) -> None:
-        """Display the data using the normal poutput method."""
-        self.poutput(self.data)
-
-    def do_pretty(self, _) -> None:
-        """Display the JSON data in a pretty way using rich."""
 
-        json_renderable = JSON.from_data(
-            self.data,
-            indent=2,
-            highlight=True,
-            skip_keys=False,
-            ensure_ascii=False,
-            check_circular=True,
-            allow_nan=True,
-            default=None,
-            sort_keys=False,
-        )
-        self.poutput(json_renderable)
+    def do_pretty(self, _: cmd2.Statement) -> None:
+        """Print an object using ppretty()."""
+        self.ppretty(EXAMPLE_DATA)
 
 
 if __name__ == '__main__':

tests/test_cmd2.py

@@ -3490,6 +3490,46 @@ def test_ppaged_terminal_restoration_oserror(outsim_app, monkeypatch) -> None:
     assert not termios_mock.tcsetattr.called
 
 
+def test_ppretty(base_app: cmd2.Cmd) -> None:
+    # Mock the Pretty class and the print_to() method
+    with mock.patch('cmd2.cmd2.Pretty') as mock_pretty, mock.patch.object(cmd2.Cmd, 'print_to') as mock_print_to:
+        # Set up the mock return value for Pretty
+        mock_pretty_obj = mock.Mock()
+        mock_pretty.return_value = mock_pretty_obj
+
+        test_obj = {"key": "value"}
+
+        # Call ppretty() with some custom arguments
+        base_app.ppretty(
+            test_obj,
+            indent_size=2,
+            max_depth=5,
+            expand_all=True,
+            end="\n\n",
+        )
+
+        # Verify Pretty was instantiated with the correct arguments
+        mock_pretty.assert_called_once_with(
+            test_obj,
+            indent_size=2,
+            indent_guides=True,
+            max_length=None,
+            max_string=None,
+            max_depth=5,
+            expand_all=True,
+            overflow="ignore",
+        )
+
+        # Verify print_to() was called with the mock pretty object and soft_wrap=True
+        # It should default to self.stdout when no file is provided
+        mock_print_to.assert_called_once_with(
+            base_app.stdout,
+            mock_pretty_obj,
+            soft_wrap=True,
+            end="\n\n",
+        )
+
+
 # we override cmd.parseline() so we always get consistent
 # command parsing by parent methods we don't override
 # don't need to test all the parsing logic here, because