MAINT: remove filling in missing value and ffill before coercing column
MAINT: remove filling in missing value and ffill before coercing column

bartosh/zipline,magne-max/zipline-ja,quantopian/zipline,wilsonkichoi/zipline,humdings/zipline,wilsonkichoi/zipline,magne-max/zipline-ja,quantopian/zipline,florentchandelier/zipline,enigmampc/catalyst,alphaBenj/zipline,florentchandelier/zipline,humdings/zipline,enigmampc/catalyst,Scapogo/zipline,alphaBenj/zipline,bartosh/zipline,Scapogo/zipline