Shifting non-NA cells to the left
问题 There are many NA's in my dataset and I need to shift all those cells (at row level) to the left. Example- my dataframe: df=data.frame(x=c("l","m",NA,NA,"p"),y=c(NA,"b","c",NA,NA),z=c("u",NA,"w","x","y")) df x y z 1 l <NA> u 2 m b <NA> 3 <NA> c w 4 <NA> <NA> x 5 p <NA> y I want the above dataframe converted into this: x y z 1 l u NA 2 m b NA 3 c w NA 4 x <NA> NA 5 p y NA Please help. Thanks. 回答1: You can use the standard apply function: df=data.frame(x=c("l","m",NA,NA,"p"),y=c(NA,"b","c",NA