Replace ipython_genutils.py3compat. getcwd with os.cwd

voila/app.py

@@ -50,8 +50,6 @@
 
 from jupyter_core.paths import jupyter_config_path, jupyter_path
 
-from ipython_genutils.py3compat import getcwd
-
 from .paths import ROOT, STATIC_ROOT, collect_template_paths, collect_static_paths
 from .handler import VoilaHandler
 from .treehandler import VoilaTreeHandler
@@ -322,7 +320,7 @@ def _default_root_dir(self):
         if self.notebook_path:
             return os.path.dirname(os.path.abspath(self.notebook_path))
         else:
-            return getcwd()
+            return os.getcwd()
 
     def _init_asyncio_patch(self):
         """set default asyncio policy to be compatible with tornado

voila/utils.py

@@ -107,6 +107,18 @@ def inner():
     for k, v in json.loads(request_info).items():
         os.environ[k] = v
 
+def get_query_string(url: str = None) -> str:
+    """Helper function to pause the execution of notebook and wait for
+    the query string.
+    Args:
+        url (str, optional): Address to get user query string, if it is not
+        provided, `voila` will figure out from the environment variables.
+        Defaults to None.
+    Returns: The query string provided by `QueryStringSocketHandler`.
+    """
+
+    wait_for_request(url)
+    return os.getenv(ENV_VARIABLE.QUERY_STRING)
 
 def make_url(template_name, base_url, path):
     # similar to static_url, but does not assume the static prefix