Try to import from collections.abc for Python 3.3+ (#887)

* Try to import from collections.abc for Python 3.3+

pyqtgraph/graphicsItems/ImageItem.py

@@ -2,13 +2,17 @@ from __future__ import division
 
 from ..Qt import QtGui, QtCore
 import numpy as np
-import collections
 from .. import functions as fn
 from .. import debug as debug
 from .GraphicsObject import GraphicsObject
 from ..Point import Point
 from .. import getConfigOption
 
+try:
+    from collections.abc import Callable
+except ImportError:
+    # fallback for python < 3.3
+    from collections import Callable
 
 __all__ = ['ImageItem']
 
@@ -357,7 +361,7 @@ class ImageItem(GraphicsObject):
 
         # Request a lookup table if this image has only one channel
         if self.image.ndim == 2 or self.image.shape[2] == 1:
-            if isinstance(self.lut, collections.Callable):
+            if isinstance(self.lut, Callable):
                 lut = self.lut(self.image)
             else:
                 lut = self.lut
@@ -624,7 +628,7 @@ class ImageItem(GraphicsObject):
         mask = self.drawMask
         src = dk
 
-        if isinstance(self.drawMode, collections.Callable):
+        if isinstance(self.drawMode, Callable):
             self.drawMode(dk, self.image, mask, ss, ts, ev)
         else:
             src = src[ss]

pyqtgraph/pgcollections.py

@@ -10,15 +10,22 @@ Includes:
   - ThreadsafeDict, ThreadsafeList - Self-mutexed data structures
 """
 
-import threading, sys, copy, collections
-#from debug import *
+import threading
+import sys
+import copy
 
 try:
     from collections import OrderedDict
 except ImportError:
     # fallback: try to use the ordereddict backport when using python 2.6
     from ordereddict import OrderedDict
-        
+
+try:
+    from collections.abc import Sequence
+except ImportError:
+    # fallback for python < 3.3
+    from collections import Sequence
+
 
 class ReverseDict(dict):
     """extends dict so that reverse lookups are possible by requesting the key as a list of length 1:
@@ -326,7 +333,7 @@ class ProtectedDict(dict):
 
 
             
-class ProtectedList(collections.Sequence):
+class ProtectedList(Sequence):
     """
     A class allowing read-only 'view' of a list or dict. 
     The object can be treated like a normal list, but will never modify the original list it points to.
@@ -408,7 +415,7 @@ class ProtectedList(collections.Sequence):
         raise Exception("This is a list. It does not poop.")
 
 
-class ProtectedTuple(collections.Sequence):
+class ProtectedTuple(Sequence):
     """
     A class allowing read-only 'view' of a tuple.
     The object can be treated like a normal tuple, but its contents will be returned as protected objects.