make time series data frame in R

h-yoshimura :

My data I acquired were missing some parts.

DAY<-c("2011-01-01","2011-01-02","2011-01-04","2011-01-06")
ITEM<-c("apple","apple","apple","banana")
sale<-c("yes","no","yes","yes")
value<-c(100,200,100,500)

df <- data.frame(day=DAY,item=ITEM,sale=sale,value=value)


         day   item sale value
1 2011-01-01  apple  yes   100
2 2011-01-02  apple   no   200
3 2011-01-04  apple  yes   100
4 2011-01-06 banana  yes   500

↑ this is my original data. but I want following expand dataframe


bind_row=NULL
bind=NULL
for(h in 1:length(unique(df$day))){
  bind_day=as.character(unique(df$day)[h])

  for(i in 1:length(unique(df$item))){
    bind_item=as.character(unique(df$item)[i])
  for(j in 1:length(unique(df$sale))){
    bind_sale=as.character(unique(df$sale)[j])
    bind=c(bind_day,bind_item,bind_sale)
    bind_row=rbind(bind_row,bind)
  }
}
}

bind_row <- cbind(bind_row,c(100,0,0,0,0,200,0,0,100,0,0,0,0,0,500,0))


bind "2011-01-01" "apple"  "yes" "100"
bind "2011-01-01" "apple"  "no"  "0"  
bind "2011-01-01" "banana" "yes" "0"  
bind "2011-01-01" "banana" "no"  "0"  
bind "2011-01-02" "apple"  "yes" "0"  
bind "2011-01-02" "apple"  "no"  "200"
bind "2011-01-02" "banana" "yes" "0"  
bind "2011-01-02" "banana" "no"  "0"  
bind "2011-01-04" "apple"  "yes" "100"
bind "2011-01-04" "apple"  "no"  "0"  
bind "2011-01-04" "banana" "yes" "0"  
bind "2011-01-04" "banana" "no"  "0"  
bind "2011-01-06" "apple"  "yes" "0"  
bind "2011-01-06" "apple"  "no"  "0"  
bind "2011-01-06" "banana" "yes" "500"
bind "2011-01-06" "banana" "no"  "0"

how can I make(transform from original data to expand data) this dataframe in R ? (or python ?)

this script soooo slow. could you help me ?

thank you.

Ronak Shah :

We can use complete from tidyr in R.

tidyr::complete(df, day, item, sale, fill = list(value = 0))

#    day        item   sale  value
#   <fct>      <fct>  <fct> <dbl>
# 1 2011-01-01 apple  no        0
# 2 2011-01-01 apple  yes     100
# 3 2011-01-01 banana no        0
# 4 2011-01-01 banana yes       0
# 5 2011-01-02 apple  no      200
# 6 2011-01-02 apple  yes       0
# 7 2011-01-02 banana no        0
# 8 2011-01-02 banana yes       0
# 9 2011-01-04 apple  no        0
#10 2011-01-04 apple  yes     100
#11 2011-01-04 banana no        0
#12 2011-01-04 banana yes       0
#13 2011-01-06 apple  no        0
#14 2011-01-06 apple  yes       0
#15 2011-01-06 banana no        0
#16 2011-01-06 banana yes     500