在 R 中循环多个数据帧

Question

I am wondering whether it's possible to loop data frames and change the contents of each field.

There are dataframes like df1, df2, df3, ... df100

In each dataframe, there are food columns having a, b

I want to change each a and b in df$food to apple, banana!

for (i in 1:100){
    paste('df', i, '$food') <- factor(paste('df', i, '$food'), level = c(a,b), labels = c("apple","banana"))
}

Do you think looping like above is possible?

Answer 1

It would be easier if you put them in a list of dataframes and use lapply .

result <- lapply(mget(paste0('df', 1:100)), function(x) transform(x, 
             food = factor(food, level=c("a","b"), labels=c("apple","banana"))))

Update the original dataframes back.

list2env(result, .GlobalEnv)