r - How to remove a column and increase count of rows based on the value of the columns

Question

I'm relatively new to R. I have a data frame with 939 rows that looks like this:

cuisine	Number.of.order	Customer_id
Fastfood	2	1
cakes	3	1
Western	4	2
Chinese	5	3

What i want is to get rid of the Numbers.of.order column and add the values inside the column as addition rows.

Something like this:

cuisine	Customer_id
Fastfood	1
Fastfood	1
cakes	1
cakes	1
cakes	1
Western	2
Western	2
Western	2
Western	2
Chinese	3
Chinese	3
Chinese	3
Chinese	3
Chinese	3

Im doing this so that I can convert it into a transaction dataframe for association rules.

Any help would be greatly appreciated!!

标签： rdataframe

Answer 1

base R一个选项rep

out <- df1[rep(seq_len(nrow(df1)), df1$Number.of.order), -2]
row.names(out) <- NULL

-输出

out
    cuisine Customer_id
1  Fastfood           1
2  Fastfood           1
3     cakes           1
4     cakes           1
5     cakes           1
6   Western           2
7   Western           2
8   Western           2
9   Western           2
10  Chinese           3
11  Chinese           3
12  Chinese           3
13  Chinese           3
14  Chinese           3