This page tracks porting progress of Python 3. The epic covering the initial port was 

PackageJIRAOwner
baseTim Jenness
pex_exceptionsTim Jenness
utilsTim Jenness
pex_policyTim Jenness
daf_baseTim Jenness
pex_loggingTim Jenness
pex_configTim Jenness
logTim Jenness
ndarrayTim Jenness
daf_persistenceTim Jenness
afwTim Jenness
skymapUnknown User (jmatt)
geomPaul Price
daf_butlerUtilsUnknown User (npease)
psfexDone, no python sourceNate Lust
obs_testRussell Owen
shapeletNate Lust
skypixPaul Price
pipe_baseRussell Owen
db

Andy Salnikov
catAndy Salnikov
mysqlpythonBrian Van Klaveren
display_ds9David Shupe
coadd_utilsRussell Owen
ctrl_eventsSteve Pietrowicz
ctrl_poolPaul Price
ctrl_orcaSteve Pietrowicz
ctrl_provenanceRussell Owen
ctrl_statsSteve Pietrowicz
ctrl_executeSteve Pietrowicz
ctrl_platform_lsst 
ctrl_platform_gordon 
pykg_configTim Jenness
meas_baseRussell Owen
meas_algorithms 
meas_extensions_photometryKron  
meas_extensions_simpleShape  
meas_extensions_psfex  
meas_deblender  
meas_extensions_shapeHSM  
meas_astrom 
meas_modelfit 
pipe_tasks 
coadd_chisquaredRussell Owen
esutil 
scisqlBrian Van Klaveren
astrometry_netTim Jenness
ip_isr 
ip_diffim 
datarel 
obs_lsstSim  
obs_subaru  
obs_decam  
obs_sdss  
obs_cfht  
lmfit