Improve py3 compatibility

12 jobs for py3 in 6 minutes and 54 seconds (queued for 6 seconds)
Status Job ID Name Coverage
  Build
passed #78844
conda-linux
build_linux_27

00:02:42

passed #78845
conda-linux
build_linux_35

00:03:11

passed #78846
conda-linux
build_linux_36

00:02:59

passed #78847
conda-macosx
build_macosx_27

00:02:23

passed #78848
conda-macosx
build_macosx_35

00:02:05

passed #78849
conda-macosx
build_macosx_36

00:02:23

 
  Test
passed #78850
conda-linux
test_linux_27

00:03:35

54.0%
passed #78851
conda-linux
test_linux_35

00:03:05

45.0%
passed #78852
conda-linux
test_linux_36

00:03:05

45.0%
passed #78853
conda-macosx
test_macosx_27

00:02:45

54.0%
passed #78854
conda-macosx
test_macosx_35

00:02:43

54.0%
passed #78855
conda-macosx
test_macosx_36

00:02:43

54.0%