Don't use [] and {} as default arguments in python functions
Don't use [] and {} as default arguments in python functions

Summary: This is problematic as these objects get instantiated once when the function is defined and not each time it is invoked meaning that if the function modifies the object it's going to be modified for all subsequent invokations.

Test Plan: buck test test/com/facebook/buck/json/...

Reviewed By: marcinkosiba

fbshipit-source-id: f84474d

zpao/buck,illicitonion/buck,OkBuilds/buck,darkforestzero/buck,illicitonion/buck,vschs007/buck,marcinkwiatkowski/buck,raviagarwal7/buck,davido/buck,davido/buck,OkBuilds/buck,brettwooldridge/buck,robbertvanginkel/buck,grumpyjames/buck,facebook/buck,brettwooldridge/buck,romanoid/buck,shybovycha/buck,illicitonion/buck,grumpyjames/buck,shs96c/buck,LegNeato/buck,LegNeato/buck,darkforestzero/buck,marcinkwiatkowski/buck,justinmuller/buck,illicitonion/buck,sdwilsh/buck,shybovycha/buck,shs96c/buck,grumpyjames/buck,shybovycha/buck,raviagarwal7/buck,sdwilsh/buck,illicitonion/buck,ilya-klyuchnikov/buck,illicitonion/buck,sdwilsh/buck,JoelMarcey/buck,OkBuilds/buck,janicduplessis/buck,zhan-xiong/buck,SeleniumHQ/buck,rmaz/buck,zhan-xiong/buck,janicduplessis/buck,zhan-xiong/buck,rmaz/buck,grumpyjames/buck,shs96c/buck,zpao/buck,JoelMarcey/buck,shs96c/buck,OkBuilds/buck,marcinkwiatkowski/buck,k21/buck,zhan-xiong/buck,romanoid/buck,JoelMarcey/buck,justinmuller/buck,sdwilsh/buck,ilya-klyuchnikov/buck,JoelMarcey/buck,k21/buck,zhan-xiong/buck,sdwilsh/buck,marcinkwiatkowski/buck,darkforestzero/buck,rmaz/buck,daedric/buck,shs96c/buck,marcinkwiatkowski/buck,SeleniumHQ/buck,rmaz/buck,SeleniumHQ/buck,SeleniumHQ/buck,k21/buck,grumpyjames/buck,justinmuller/buck,romanoid/buck,shs96c/buck,JoelMarcey/buck,facebook/buck,rmaz/buck,Addepar/buck,rmaz/buck,zpao/buck,shybovycha/buck,rmaz/buck,davido/buck,shs96c/buck,clonetwin26/buck,robbertvanginkel/buck,janicduplessis/buck,justinmuller/buck,raviagarwal7/buck,dsyang/buck,janicduplessis/buck,zhan-xiong/buck,davido/buck,LegNeato/buck,brettwooldridge/buck,rmaz/buck,davido/buck,Addepar/buck,darkforestzero/buck,vschs007/buck,dsyang/buck,daedric/buck,shybovycha/buck,Addepar/buck,justinmuller/buck,janicduplessis/buck,robbertvanginkel/buck,vschs007/buck,marcinkwiatkowski/buck,ilya-klyuchnikov/buck,robbertvanginkel/buck,Addepar/buck,grumpyjames/buck,nguyentruongtho/buck,Addepar/buck,ilya-klyuchnikov/buck,dsyang/buck,daedric/buck,kageiit/buck,dsyang/buck,OkBuilds/buck,davido/buck,raviagarwal7/buck,Addepar/buck,daedric/buck,romanoid/buck,davido/buck,daedric/buck,robbertvanginkel/buck,romanoid/buck,darkforestzero/buck,vschs007/buck,kageiit/buck,SeleniumHQ/buck,daedric/buck,zhan-xiong/buck,sdwilsh/buck,rmaz/buck,k21/buck,LegNeato/buck,brettwooldridge/buck,darkforestzero/buck,grumpyjames/buck,ilya-klyuchnikov/buck,k21/buck,zpao/buck,facebook/buck,davido/buck,brettwooldridge/buck,k21/buck,ilya-klyuchnikov/buck,clonetwin26/buck,grumpyjames/buck,robbertvanginkel/buck,vschs007/buck,LegNeato/buck,JoelMarcey/buck,k21/buck,clonetwin26/buck,Addepar/buck,vschs007/buck,k21/buck,SeleniumHQ/buck,marcinkwiatkowski/buck,vschs007/buck,robbertvanginkel/buck,shybovycha/buck,dsyang/buck,robbertvanginkel/buck,kageiit/buck,facebook/buck,clonetwin26/buck,raviagarwal7/buck,robbertvanginkel/buck,ilya-klyuchnikov/buck,Addepar/buck,robbertvanginkel/buck,Addepar/buck,darkforestzero/buck,JoelMarcey/buck,daedric/buck,nguyentruongtho/buck,justinmuller/buck,SeleniumHQ/buck,shybovycha/buck,dsyang/buck,romanoid/buck,JoelMarcey/buck,davido/buck,clonetwin26/buck,LegNeato/buck,raviagarwal7/buck,janicduplessis/buck,justinmuller/buck,justinmuller/buck,rmaz/buck,shs96c/buck,dsyang/buck,k21/buck,darkforestzero/buck,janicduplessis/buck,shs96c/buck,janicduplessis/buck,justinmuller/buck,raviagarwal7/buck,nguyentruongtho/buck,raviagarwal7/buck,romanoid/buck,shs96c/buck,romanoid/buck,SeleniumHQ/buck,rmaz/buck,clonetwin26/buck,shybovycha/buck,vschs007/buck,clonetwin26/buck,daedric/buck,romanoid/buck,zhan-xiong/buck,brettwooldridge/buck,zpao/buck,JoelMarcey/buck,marcinkwiatkowski/buck,daedric/buck,janicduplessis/buck,ilya-klyuchnikov/buck,sdwilsh/buck,illicitonion/buck,shybovycha/buck,illicitonion/buck,k21/buck,facebook/buck,SeleniumHQ/buck,raviagarwal7/buck,shybovycha/buck,LegNeato/buck,vschs007/buck,sdwilsh/buck,illicitonion/buck,robbertvanginkel/buck,marcinkwiatkowski/buck,facebook/buck,justinmuller/buck,darkforestzero/buck,vschs007/buck,davido/buck,marcinkwiatkowski/buck,zhan-xiong/buck,illicitonion/buck,Addepar/buck,marcinkwiatkowski/buck,illicitonion/buck,OkBuilds/buck,davido/buck,rmaz/buck,nguyentruongtho/buck,shybovycha/buck,raviagarwal7/buck,k21/buck,SeleniumHQ/buck,darkforestzero/buck,zhan-xiong/buck,k21/buck,sdwilsh/buck,clonetwin26/buck,davido/buck,Addepar/buck,shs96c/buck,daedric/buck,SeleniumHQ/buck,brettwooldridge/buck,justinmuller/buck,JoelMarcey/buck,darkforestzero/buck,clonetwin26/buck,JoelMarcey/buck,romanoid/buck,shs96c/buck,zhan-xiong/buck,daedric/buck,clonetwin26/buck,dsyang/buck,OkBuilds/buck,janicduplessis/buck,kageiit/buck,raviagarwal7/buck,OkBuilds/buck,LegNeato/buck,OkBuilds/buck,clonetwin26/buck,ilya-klyuchnikov/buck,zhan-xiong/buck,romanoid/buck,romanoid/buck,grumpyjames/buck,raviagarwal7/buck,OkBuilds/buck,dsyang/buck,shybovycha/buck,illicitonion/buck,dsyang/buck,JoelMarcey/buck,sdwilsh/buck,Addepar/buck,rmaz/buck,vschs007/buck,marcinkwiatkowski/buck,brettwooldridge/buck,justinmuller/buck,zpao/buck,brettwooldridge/buck,illicitonion/buck,sdwilsh/buck,JoelMarcey/buck,LegNeato/buck,brettwooldridge/buck,kageiit/buck,shybovycha/buck,SeleniumHQ/buck,zhan-xiong/buck,kageiit/buck,kageiit/buck,dsyang/buck,ilya-klyuchnikov/buck,janicduplessis/buck,clonetwin26/buck,grumpyjames/buck,sdwilsh/buck,OkBuilds/buck,brettwooldridge/buck,zpao/buck,facebook/buck,vschs007/buck,davido/buck,nguyentruongtho/buck,romanoid/buck,k21/buck,ilya-klyuchnikov/buck,clonetwin26/buck,grumpyjames/buck,janicduplessis/buck,daedric/buck,sdwilsh/buck,justinmuller/buck,darkforestzero/buck,OkBuilds/buck,grumpyjames/buck,LegNeato/buck,shs96c/buck,vschs007/buck,ilya-klyuchnikov/buck,Addepar/buck,daedric/buck,marcinkwiatkowski/buck,raviagarwal7/buck,nguyentruongtho/buck,SeleniumHQ/buck,brettwooldridge/buck,OkBuilds/buck,ilya-klyuchnikov/buck,brettwooldridge/buck,LegNeato/buck,dsyang/buck,robbertvanginkel/buck,LegNeato/buck,robbertvanginkel/buck,nguyentruongtho/buck,LegNeato/buck,darkforestzero/buck,dsyang/buck