Fix lasso_selector_demo.py on Python 3

Author: cgohlke

examples/widgets/lasso_selector_demo.py

@@ -1,8 +1,16 @@
+from __future__ import print_function
+
 import numpy as np
 
 from matplotlib.widgets import LassoSelector
 from matplotlib.path import Path
 
+try:
+    raw_input
+except NameError:
+    # Python 3
+    raw_input = input
+
 
 class SelectFromCollection(object):
     """Select indices from a matplotlib collection using `LassoSelector`.
@@ -65,18 +73,17 @@ def disconnect(self):
     plt.ion()
     data = np.random.rand(100, 2)
 
-    subplot_kw = dict(xlim=(0,1), ylim=(0,1), autoscale_on=False)
+    subplot_kw = dict(xlim=(0, 1), ylim=(0, 1), autoscale_on=False)
     fig, ax = plt.subplots(subplot_kw=subplot_kw)
 
     pts = ax.scatter(data[:, 0], data[:, 1], s=80)
     selector = SelectFromCollection(ax, pts)
 
     plt.draw()
     raw_input('Press any key to accept selected points')
-    print "Selected points:"
-    print selector.xys[selector.ind]
+    print("Selected points:")
+    print(selector.xys[selector.ind])
     selector.disconnect()
 
     # Block end of script so you can check that the lasso is disconnected.
     raw_input('Press any key to quit')
-