Don't use cache in Order.
Don't use cache in Order.

Timings with "py.test sympy/series/":

Before: 34.94
After: 34.83

Lesson learned: caching is evil.

Kirr's comment in the review:

I'd say "think 7 times before introducing a cache..."

Shaswat27/sympy,jamesblunt/sympy,KevinGoodsell/sympy,grevutiu-gabriel/sympy,hazelnusse/sympy-old,AkademieOlympia/sympy,iamutkarshtiwari/sympy,debugger22/sympy,kaichogami/sympy,lidavidm/sympy,kumarkrishna/sympy,wanglongqi/sympy,ga7g08/sympy,rahuldan/sympy,cswiercz/sympy,pernici/sympy,saurabhjn76/sympy,Titan-C/sympy,asm666/sympy,maniteja123/sympy,kumarkrishna/sympy,MridulS/sympy,ga7g08/sympy,wyom/sympy,beni55/sympy,abhiii5459/sympy,amitjamadagni/sympy,chaffra/sympy,drufat/sympy,iamutkarshtiwari/sympy,sahmed95/sympy,Arafatk/sympy,Davidjohnwilson/sympy,souravsingh/sympy,debugger22/sympy,saurabhjn76/sympy,yashsharan/sympy,kaushik94/sympy,jerli/sympy,cswiercz/sympy,pandeyadarsh/sympy,toolforger/sympy,AkademieOlympia/sympy,cccfran/sympy,Arafatk/sympy,shikil/sympy,mafiya69/sympy,beni55/sympy,liangjiaxing/sympy,emon10005/sympy,hargup/sympy,pbrady/sympy,kaushik94/sympy,farhaanbukhsh/sympy,kaushik94/sympy,emon10005/sympy,skirpichev/omg,madan96/sympy,debugger22/sympy,maniteja123/sympy,jaimahajan1997/sympy,MechCoder/sympy,sahilshekhawat/sympy,pbrady/sympy,meghana1995/sympy,atsao72/sympy,Designist/sympy,Gadal/sympy,Sumith1896/sympy,wyom/sympy,atsao72/sympy,drufat/sympy,ga7g08/sympy,yukoba/sympy,kumarkrishna/sympy,diofant/diofant,toolforger/sympy,kevalds51/sympy,Gadal/sympy,bukzor/sympy,abhiii5459/sympy,ChristinaZografou/sympy,Davidjohnwilson/sympy,garvitr/sympy,Designist/sympy,jbbskinny/sympy,ahhda/sympy,Shaswat27/sympy,lidavidm/sympy,oliverlee/sympy,vipulroxx/sympy,wanglongqi/sympy,sunny94/temp,kmacinnis/sympy,Titan-C/sympy,Shaswat27/sympy,kaichogami/sympy,madan96/sympy,shipci/sympy,Curious72/sympy,sampadsaha5/sympy,dqnykamp/sympy,hargup/sympy,postvakje/sympy,MridulS/sympy,postvakje/sympy,amitjamadagni/sympy,Titan-C/sympy,bukzor/sympy,abloomston/sympy,vipulroxx/sympy,mafiya69/sympy,kmacinnis/sympy,iamutkarshtiwari/sympy,skidzo/sympy,oliverlee/sympy,hargup/sympy,wyom/sympy,liangjiaxing/sympy,jbbskinny/sympy,AkademieOlympia/sympy,meghana1995/sympy,kaichogami/sympy,cccfran/sympy,jbaayen/sympy,ChristinaZografou/sympy,jerli/sympy,grevutiu-gabriel/sympy,ryanGT/sympy,jerli/sympy,MechCoder/sympy,yashsharan/sympy,Curious72/sympy,Sumith1896/sympy,chaffra/sympy,Mitchkoens/sympy,wanglongqi/sympy,Designist/sympy,lindsayad/sympy,vipulroxx/sympy,rahuldan/sympy,hazelnusse/sympy-old,abloomston/sympy,minrk/sympy,sahilshekhawat/sympy,yashsharan/sympy,VaibhavAgarwalVA/sympy,madan96/sympy,saurabhjn76/sympy,mcdaniel67/sympy,sunny94/temp,Arafatk/sympy,bukzor/sympy,sahmed95/sympy,meghana1995/sympy,sahmed95/sympy,lidavidm/sympy,skidzo/sympy,cccfran/sympy,flacjacket/sympy,hrashk/sympy,yukoba/sympy,grevutiu-gabriel/sympy,hrashk/sympy,liangjiaxing/sympy,Sumith1896/sympy,ahhda/sympy,lindsayad/sympy,farhaanbukhsh/sympy,Davidjohnwilson/sympy,kevalds51/sympy,souravsingh/sympy,kmacinnis/sympy,aktech/sympy,jamesblunt/sympy,atreyv/sympy,maniteja123/sympy,moble/sympy,pbrady/sympy,garvitr/sympy,dqnykamp/sympy,VaibhavAgarwalVA/sympy,jamesblunt/sympy,shipci/sympy,tovrstra/sympy,sampadsaha5/sympy,aktech/sympy,Mitchkoens/sympy,abloomston/sympy,shikil/sympy,lindsayad/sympy,postvakje/sympy,MridulS/sympy,rahuldan/sympy,asm666/sympy,drufat/sympy,atsao72/sympy,AunShiLord/sympy,farhaanbukhsh/sympy,moble/sympy,cswiercz/sympy,atreyv/sympy,kevalds51/sympy,jaimahajan1997/sympy,jaimahajan1997/sympy,mcdaniel67/sympy,MechCoder/sympy,sunny94/temp,aktech/sympy,ahhda/sympy,shikil/sympy,beni55/sympy,VaibhavAgarwalVA/sympy,mcdaniel67/sympy,AunShiLord/sympy,Gadal/sympy,shipci/sympy,abhiii5459/sympy,fperez/sympy,souravsingh/sympy,Vishluck/sympy,hrashk/sympy,sahilshekhawat/sympy,pandeyadarsh/sympy,garvitr/sympy,emon10005/sympy,ChristinaZografou/sympy,toolforger/sympy,chaffra/sympy,minrk/sympy,Vishluck/sympy,atreyv/sympy,dqnykamp/sympy,Mitchkoens/sympy,mafiya69/sympy,yukoba/sympy,Vishluck/sympy,skidzo/sympy,oliverlee/sympy,srjoglekar246/sympy,jbbskinny/sympy,asm666/sympy,sampadsaha5/sympy,Curious72/sympy,pandeyadarsh/sympy,mattpap/sympy-polys,moble/sympy,AunShiLord/sympy