Reverts the dynesty print function to the dynesty built-in

Changes to dynesty have improved their built in print function since we
first overwrote it. There is also more information given such as the
bounds and it now uses tqdm which reduces the stdout overhead.

bilby/core/sampler/dynesty.py

@@ -6,6 +6,7 @@ import sys
 import pickle
 import signal
 
+import tqdm
 import matplotlib.pyplot as plt
 import numpy as np
 from pandas import DataFrame
@@ -159,11 +160,12 @@ class Dynesty(NestedSampler):
             self.kwargs['walks'] = self.ndim * 10
         if not self.kwargs['update_interval']:
             self.kwargs['update_interval'] = int(0.6 * self.kwargs['nlive'])
-        if not self.kwargs['print_func']:
+        if self.kwargs['print_func'] is None:
             self.kwargs['print_func'] = self._print_func
+            self.pbar = tqdm.tqdm(file=sys.stdout)
         Sampler._verify_kwargs_against_default_kwargs(self)
 
-    def _print_func(self, results, niter, ncall, dlogz, *args, **kwargs):
+    def _print_func(self, results, niter, ncall=None, dlogz=None, *args, **kwargs):
         """ Replacing status update for dynesty.result.print_func """
 
         # Extract results at the current iteration.
@@ -184,18 +186,20 @@ class Dynesty(NestedSampler):
             loglstar = -np.inf
 
         if self.use_ratio:
-            key = 'logz ratio'
+            key = 'logz-ratio'
         else:
             key = 'logz'
 
         # Constructing output.
-        raw_string = "\r {}| {}={:6.3f} +/- {:6.3f} | dlogz: {:6.3f} > {:6.3f}"
-        print_str = raw_string.format(
-            niter, key, logz, logzerr, delta_logz, dlogz)
+        string = []
+        string.append("bound:{:d}".format(bounditer))
+        string.append("ncall:{:d}".format(ncall))
+        string.append("eff:{:0.1f}%".format(eff))
+        string.append("{}={:0.2f}+/-{:0.2f}".format(key, logz, logzerr))
+        string.append("dlogz:{:0.3f}>{:0.2f}".format(delta_logz, dlogz))
 
-        # Printing.
-        sys.stdout.write(print_str)
-        sys.stdout.flush()
+        self.pbar.set_postfix_str(" ".join(string), refresh=False)
+        self.pbar.update(niter - self.pbar.n)
 
     def _apply_dynesty_boundaries(self):
         self._periodic = list()
@@ -233,6 +237,7 @@ class Dynesty(NestedSampler):
 
         # Flushes the output to force a line break
         if self.kwargs["verbose"]:
+            self.pbar.close()
             print("")
 
         check_directory_exists_and_if_not_mkdir(self.outdir)
@@ -401,6 +406,7 @@ class Dynesty(NestedSampler):
             NestedSampler to write to disk.
         """
         check_directory_exists_and_if_not_mkdir(self.outdir)
+        print("")
         logger.info("Writing checkpoint file {}".format(self.resume_file))
 
         end_time = datetime.datetime.now()