Render nested progress bars in the same container in IPython. Fixes r…

…endering issues in VSCode. See: microsoft/vscode-jupyter#9397.

tqdm/notebook.py

@@ -37,22 +37,24 @@
         if IPY == 32:
             from IPython.html.widgets import HTML
             from IPython.html.widgets import FloatProgress as IProgress
-            from IPython.html.widgets import HBox
+            from IPython.html.widgets import HBox, VBox
             IPY = 3
         else:
             from ipywidgets import HTML
             from ipywidgets import FloatProgress as IProgress
-            from ipywidgets import HBox
+            from ipywidgets import HBox, VBox
     except ImportError:
         try:  # IPython 2.x
             from IPython.html.widgets import HTML
             from IPython.html.widgets import ContainerWidget as HBox
+            from IPython.html.widgets import ContainerWidget as VBox
             from IPython.html.widgets import FloatProgressWidget as IProgress
             IPY = 2
         except ImportError:
             IPY = 0
             IProgress = None
             HBox = object
+            VBox = object
 
     try:
         from IPython.display import display  # , clear_output
@@ -178,6 +180,9 @@ def display(self, msg=None, pos=None,
 
         # Special signal to close the bar
         if close and pbar.bar_style != 'danger':  # hide only if no error
+            # Remove self.container from the list of children of outer_container
+            self.outer_container.children = tuple(
+                c for c in self.outer_container.children if c is not self.container)
             try:
                 self.container.close()
             except AttributeError:
@@ -198,6 +203,10 @@ def colour(self, bar_color):
         if hasattr(self, 'container'):
             self.container.children[-2].style.bar_color = bar_color
 
+    @classmethod
+    def get_first_inst(cls, instance):
+        return min(cls._instances, key=lambda x: getattr(x, 'pos', float('inf')))
+
     def __init__(self, *args, **kwargs):
         """
         Supports the usual `tqdm.tqdm` parameters as well as those listed below.
@@ -230,11 +239,21 @@ def __init__(self, *args, **kwargs):
         # Replace with IPython progress bar display (with correct total)
         unit_scale = 1 if self.unit_scale is True else self.unit_scale or 1
         total = self.total * unit_scale if self.total else self.total
+
+        first_inst = self.get_first_inst(self)
+        iam_first = first_inst is self
+        if iam_first:
+            self.outer_container = VBox()
+        else:
+            self.outer_container = first_inst.outer_container
+
         self.container = self.status_printer(self.fp, total, self.desc, self.ncols)
+        self.outer_container.children += (self.container,)
+
         self.container.pbar = proxy(self)
         self.displayed = False
-        if display_here and self.delay <= 0:
-            display(self.container)
+        if display_here and self.delay <= 0 and iam_first:
+            display(self.outer_container)
             self.displayed = True
         self.disp = self.display
         self.colour = colour