Extract text using regex in R

Question

I read the text file with below data and am trying to convert it to a dataframe

Id:   1
ASIN: 0827229534
  title: Patterns of Preaching: A Sermon Sampler
  group         


        

Answer 1

Here is a different approach using separate_rows and spread to reformat the text file into a dataframe:

text = readLines(path_to_textfile)

library(dplyr)
library(tidyr)

data.frame(text = text) %>%
  separate_rows(text, sep = "(?<=\\d)\\s+(?=[a-z])") %>%
  extract(text, c("title", "value"), regex = "(?i)([a-z]+):(.+)") %>%
  filter(!title %in% c("reviews", "downloaded")) %>%
  group_by(title) %>%
  mutate(id = 1:n()) %>%
  spread(title, value) %>%
  select(-id)

Result:

         ASIN group   Id rating salesrank
1  0827229534  Book    1      5    396585
2    12412441  Book    2     10   4225352
                                                         similar
1  5  0804215715  156101074X  0687023955  0687074231  082721619X
2                                         1241242 1412414 124124
                                     title
1  Patterns of Preaching: A Sermon Sampler
2                                Patterns2

Data:

Id:   1
ASIN: 0827229534
  title: Patterns of Preaching: A Sermon Sampler
  group: Book
  salesrank: 396585
  similar: 5  0804215715  156101074X  0687023955  0687074231  082721619X
  reviews: total: 2  downloaded: 2  avg rating: 5
Id:   2
ASIN: 12412441
  title: Patterns2
  group: Book
  salesrank: 4225352
  similar: 1241242 1412414 124124
  reviews: total: 2  downloaded: 2  avg rating: 10

Note:

Leave an extra blank row at the end of the text file. Otherwise readLines would return an error when attempting to read in the file.