add dask submodule

- fixes #278
- replaces/closes #279
- based on `tqdm.keras`

tqdm/dask.py

@@ -0,0 +1,45 @@
+from __future__ import absolute_import
+from .auto import tqdm as tqdm_auto
+from functools import partial
+from dask.callbacks import Callback
+__author__ = {"github.com/": ["casperdcl"]}
+__all__ = ['TqdmCallback']
+
+
+class TqdmCallback(Callback):
+    """`dask` callback for task progress"""
+    def __init__(self, start=None, start_state=None, pretask=None,
+                 posttask=None, finish=None, tqdm_class=tqdm_auto,
+                 **tqdm_kwargs):
+        """
+        Parameters
+        ----------
+        tqdm_class : optional
+            `tqdm` class to use for bars [default: `tqdm.auto.tqdm`].
+        tqdm_kwargs  : optional
+            Any other arguments used for all bars.
+        """
+        super(TqdmCallback, self).__init__(
+            start=start, start_state=start_state, pretask=pretask,
+            posttask=posttask, finish=finish)
+        if tqdm_kwargs:
+            tqdm_class = partial(tqdm_class, **tqdm_kwargs)
+        self.tqdm_class = tqdm_class
+
+    def _start_state(self, _, state):
+        self.pbar = self.tqdm_class(total=sum(
+            len(state[k]) for k in ['ready', 'waiting', 'running', 'finished']))
+
+    def _posttask(self, *args, **kwargs):
+        self.pbar.update()
+
+    def _finish(self, *args, **kwargs):
+        self.pbar.close()
+
+    def display(self):
+        """displays in the current cell in Notebooks"""
+        container = getattr(self.bar, 'container', None)
+        if container is None:
+            return
+        from .notebook import display
+        display(container)