prevent creation of new px.default properties at run time

Author: Joseph Damiba

app.py

@@ -0,0 +1,10 @@
+import plotly.express as px
+px.defaults.template = "ggplot2"
+px.defaults.color_continuous_scale = px.colors.sequential.Blackbody
+px.defaults.width = 600
+px.defaults.height = 400
+px.defaults.blerd = "hlkjhlkjhjh"
+
+df = px.data.iris()
+fig = px.scatter(df, x="sepal_width", y="sepal_length", color="sepal_length", width=400)
+fig.show()

packages/python/plotly/plotly/express/_core.py

@@ -16,6 +16,8 @@
 
 
 class PxDefaults(object):
+    __slots__ = ['template', 'width', 'height', 'color_discrete_sequence', 'color_continuous_scale', 'symbol_sequence', 'line_dash_sequence', 'size_max']
+    
     def __init__(self):
         self.template = None
         self.width = None
@@ -25,8 +27,7 @@ def __init__(self):
         self.symbol_sequence = None
         self.line_dash_sequence = None
         self.size_max = 20
-
-
+        
 defaults = PxDefaults()
 del PxDefaults
 
@@ -740,6 +741,7 @@ def one_group(x):
 
 def apply_default_cascade(args):
     # first we apply px.defaults to unspecified args
+   
 
     for param in (
         ["color_discrete_sequence", "color_continuous_scale"]