Implement sampling progress bar (#1534)

Summary:
Pull Request resolved: #1534

In this diff:
We are implementing a progress bar for the sampling stage of bart_model.py and eliminating the print to stdout. See T125518201.

Reviewed By: horizon-blue

Differential Revision: D37702073

fbshipit-source-id: 1987fb7c72d9358ade247d0c3f621c8510b97ae6

src/beanmachine/ppl/experimental/causal_inference/models/bart/bart_model.py

@@ -25,6 +25,7 @@
 from beanmachine.ppl.experimental.causal_inference.models.bart.tree import Tree
 from torch.distributions.gamma import Gamma
 from torch.distributions.normal import Normal
+from tqdm.auto import trange
 
 
 class BART:
@@ -114,8 +115,7 @@ def fit(
         self.samples = {"trees": [], "sigmas": []}
         self._init_trees(X)
 
-        for iter_id in range(num_burn + num_samples):
-            print(f"Sampling iteration {iter_id}")
+        for iter_id in trange(num_burn + num_samples):
             trees, sigma = self._step()
             self._all_trees = trees
             if iter_id >= num_burn: