1. Learn
    2. /
  2. Courses
    3. /
  3. String Manipulation with stringr in R

Exercise

Some simple text statistics

Generally, specifying simplify = TRUE will give you output that is easier to work with, but you'll always get n pieces (even if some are empty, "").

Sometimes, you want to know how many pieces a string can be split into, or you want to do something with every piece before moving to a simpler structure. This is a situation where you don't want to simplify and you'll have to process the output with something like lapply().

As an example, you'll be performing some simple text statistics on your lines from Alice's Adventures in Wonderland from Chapter 1. Your goal will be to calculate how many words are in each line, and the average length of words in each line.

To do these calculations, you'll need to split the lines into words. One way to break a sentence into words is to split on an empty space " ". This is a little naive because, for example, it wouldn't pick up words separated by a newline escape sequence like in "two\nwords", but since this situation doesn't occur in your lines, it will do.

Instructions

100 XP

We've put lines a vector with three strings, each corresponding to a line in your workspace.

  • Split lines into words. Assign the resulting list to words.
  • Use lapply() to apply length() to each element in words to count the number of words in each line.
  • Use lapply() to apply str_length() to each element in words, to count the number of characters in each word. Assign this to word_lengths.
  • Use lapply() to apply mean() to each element in word_lengths, to find the average word length in each line.