There are two data frames, DF_A and DF_B.

DF_A:

DF_B:

I want to change good_page for each row in DF_B to the respective value in valid of DF_A. Using mutate caused an error and using a for loop didn't help either.

CodePudding user response：

In dplyr piplines:

DF_B %>% right_join(DF_A)

gives

Joining, by = "domain"
# A tibble: 18 × 3
   domain       good_page valid
   <chr>        <lgl>     <dbl>
 1 googl.nl     NA            1
 2 googl.nl     NA            1
 3 googl.nl     NA            1
 4 googl.nl     NA            1
 5 googl.nl     NA            1
 6 googl.nl     NA            1
 7 hwenzl.de    NA            0
 8 hwenzl.de    NA            0
 9 hwenzl.de    NA            0
10 aytqfis.com  NA            0
11 tokzrrtss.es NA            1
12 tokzrrtss.es NA            1
13 tokzrrtss.es NA            1
14 tokzrrtss.es NA            1
15 cnn.net      NA            0
16 cnn.net      NA            0
17 cnn.net      NA            0
18 cnn.net      NA            0

which is the bulk of the work.

CodePudding user response：

How about:

DF_C <- left_join(DF_B, DF_A, by="domain")

Or maybe some of the *_join() function family: 9.2.3 Merging data frames with *_join()