Add progress bar keywords

package/AUTHORS

@@ -210,6 +210,7 @@ Chronological list of authors
   - Moritz Schaeffler
   - Xu Hong Chen
   - Domenico Marson
+  - Egor Marin
 
 External code
 -------------

package/MDAnalysis/analysis/base.py

@@ -390,7 +390,7 @@ def _conclude(self):
         pass  # pylint: disable=unnecessary-pass
 
     def run(self, start=None, stop=None, step=None, frames=None,
-            verbose=None):
+            verbose=None, *, pbar_kwargs={}):
         """Perform the calculation
 
         Parameters
@@ -411,6 +411,10 @@ def run(self, start=None, stop=None, step=None, frames=None,
 
         verbose : bool, optional
             Turn on verbosity
+
+        pbar_kwargs : dict, optional
+            ProgressBar keywords with custom parameters regarding progress bar position, etc; 
+            see :class:`MDAnalysis.lib.log.ProgressBar` for full list.
 
 
         .. versionchanged:: 2.2.0
@@ -429,9 +433,11 @@ def run(self, start=None, stop=None, step=None, frames=None,
         self._prepare()
         logger.info("Starting analysis loop over %d trajectory frames",
                     self.n_frames)
+
         for i, ts in enumerate(ProgressBar(
                 self._sliced_trajectory,
-                verbose=verbose)):
+                verbose=verbose,
+                **pbar_kwargs)):
             self._frame_index = i
             self._ts = ts
             self.frames[i] = ts.frame

testsuite/MDAnalysisTests/analysis/test_base.py

@@ -30,7 +30,7 @@
 from numpy.testing import assert_equal, assert_almost_equal
 
 import MDAnalysis as mda
-from MDAnalysis.analysis import base
+from MDAnalysis.analysis import base, rms
 
 from MDAnalysisTests.datafiles import PSF, DCD, TPR, XTC
 from MDAnalysisTests.util import no_deprecated_call
@@ -274,6 +274,12 @@ def test_verbose_progressbar_run(u, capsys):
     actual = err.strip().split('\r')[-1]
     assert actual[:24] == expected[:24]
 
+def test_verbose_progressbar_run_with_kwargs(u, capsys):
+    an = FrameAnalysis(u.trajectory).run(verbose=True, pbar_kwargs={'desc':'custom'})
+    out, err = capsys.readouterr()
+    expected = u'custom: 100%|██████████| 98/98 [00:00<00:00, 8799.49it/s]'
+    actual = err.strip().split('\r')[-1]
+    assert actual[:24] == expected[:24]
 
 def test_incomplete_defined_analysis(u):
     with pytest.raises(NotImplementedError):