Change --viewer to open UI locally instead of from web. (#687)

* Change --viewer to open UI locally instead of from web.

* Added 'r' prefix to avoid SyntaxWarning.

scalene/scalene_parseargs.py

@@ -1,13 +1,14 @@
 import argparse
 import contextlib
+import os
 import sys
 from textwrap import dedent
 from typing import Any, List, NoReturn, Optional, Tuple
 
 from scalene.scalene_arguments import ScaleneArguments
 from scalene.scalene_version import scalene_version, scalene_date
 
-scalene_gui_url = "https://plasma-umass.org/scalene-gui/"
+scalene_gui_url = f'file:{os.path.join(os.path.dirname(__file__), "scalene-gui", "index.html")}'
 
 
 class RichArgParser(argparse.ArgumentParser):
@@ -46,7 +47,7 @@ def parse_args() -> Tuple[argparse.Namespace, List[str]]:
                 sys._exit = ScaleneParseArgs.clean_exit  # type: ignore
         defaults = ScaleneArguments()
         usage = dedent(
-            f"""[b]Scalene[/b]: a high-precision CPU and memory profiler, version {scalene_version} ({scalene_date})
+            rf"""[b]Scalene[/b]: a high-precision CPU and memory profiler, version {scalene_version} ({scalene_date})
 [link=https://github.com/plasma-umass/scalene]https://github.com/plasma-umass/scalene[/link]
 
 
@@ -155,7 +156,7 @@ def parse_args() -> Tuple[argparse.Namespace, List[str]]:
             action="store_const",
             const=True,
             default=False,
-            help=f"only opens the web UI ({scalene_gui_url})",
+            help=f"opens the Scalene web UI and exits.",
         )
         parser.add_argument(
             "--reduced-profile",