在R中定义函数时如何计算列中的观察数？

Question

I'm trying to define a function such that it will take two arguments and it will count the number of brackets in the column(morph_column) of a given dataframe based on another column(the_words). After that, I need to count the number of observations inside the Length column, for example, if the number of brackets returned for "the_words" is 1, I need to know how many items are there in the dataframe with the same Length (1). Same goes for the observations of 2,3,4,5... etc. When I try to do it with n() in dplyr, it tells me that " n() must only be used inside dplyr verbs", even though I am doing that with summarise and group_by. How can I fix this? Thank you. Here is the code:

morphemes_per_word <- function(the_words, morph_column) {
    result <- data.frame("Word" = the_words, "Length" = (stri_count_regex(morph_column, "\\[")))
    result2 <- result %>%
      dplyr::group_by(Length)
      dplyr::summarise(N = n())
    return(result2)
}

Answer 1

There is a break in the chain ( %>% ) between the group_by step and summarise

morphemes_per_word <- function(the_words, morph_column) {
    result <- data.frame(Word = the_words,
         Length = stri_count_regex(morph_column, "\\["))
    result %>%
      dplyr::group_by(Length) %>%
      dplyr::summarise(N = n())
   
}