Fix python2.6 compatibility in goldberg_radzik
Fix python2.6 compatibility in goldberg_radzik

ionanrozenfeld/networkx,farhaanbukhsh/networkx,dmoliveira/networkx,harlowja/networkx,ghdk/networkx,dmoliveira/networkx,beni55/networkx,bzero/networkx,nathania/networkx,JamesClough/networkx,OrkoHunter/networkx,farhaanbukhsh/networkx,kernc/networkx,RMKD/networkx,tmilicic/networkx,chrisnatali/networkx,dhimmel/networkx,bzero/networkx,SanketDG/networkx,debsankha/networkx,blublud/networkx,yashu-seth/networkx,dhimmel/networkx,aureooms/networkx,debsankha/networkx,chrisnatali/networkx,ionanrozenfeld/networkx,cmtm/networkx,jni/networkx,sharifulgeo/networkx,blublud/networkx,nathania/networkx,kernc/networkx,aureooms/networkx,jakevdp/networkx,dhimmel/networkx,sharifulgeo/networkx,blublud/networkx,dmoliveira/networkx,bzero/networkx,jakevdp/networkx,NvanAdrichem/networkx,harlowja/networkx,debsankha/networkx,ionanrozenfeld/networkx,jni/networkx,Sixshaman/networkx,jakevdp/networkx,jfinkels/networkx,michaelpacer/networkx,ghdk/networkx,farhaanbukhsh/networkx,chrisnatali/networkx,RMKD/networkx,ghdk/networkx,nathania/networkx,andnovar/networkx,goulu/networkx,jcurbelo/networkx,harlowja/networkx,kernc/networkx,jni/networkx,sharifulgeo/networkx,ltiao/networkx,wasade/networkx,RMKD/networkx,aureooms/networkx