Use optional rich dependency to render tracebacks, closes #1416

datasette/app.py

@@ -81,6 +81,11 @@ from .tracer import AsgiTracer
 from .plugins import pm, DEFAULT_PLUGINS, get_plugins
 from .version import __version__
 
+try:
+    import rich
+except ImportError:
+    rich = None
+
 app_root = Path(__file__).parent.parent
 
 # https://github.com/simonw/datasette/issues/283#issuecomment-781591015
@@ -1270,6 +1275,9 @@ class DatasetteRouter:
 
             pdb.post_mortem(exception.__traceback__)
 
+        if rich is not None:
+            rich.console.Console().print_exception(show_locals=True)
+
         title = None
         if isinstance(exception, Forbidden):
             status = 403

datasette/cli.py

@@ -31,6 +31,14 @@ from .utils.sqlite import sqlite3
 from .utils.testing import TestClient
 from .version import __version__
 
+# Use Rich for tracebacks if it is installed
+try:
+    from rich.traceback import install
+
+    install(show_locals=True)
+except ImportError:
+    pass
+
 
 class Config(click.ParamType):
     # This will be removed in Datasette 1.0 in favour of class Setting

setup.py

@@ -75,6 +75,7 @@ setup(
             "pytest-timeout>=1.4.2,<1.5",
             "trustme>=0.7,<0.9",
         ],
+        "rich": ["rich"],
     },
     tests_require=["datasette[test]"],
     classifiers=[