用r解析文本

Question

我有一些最初是srt的文件，格式字幕已发布。 他们通常遵循的模式如下：

Subtitle_number
Beginning_min --> Ending_min
Text

例如，这可能是srt文件的结构：

1
00:00:00,100 --> 00:00:01,500
This is the first subtitle

2
00:00:01,700 --> 00:00:02,300
of the movie

现在，我有一些“修改” srt's，由于它们在字幕编号之后立即具有字符的名称，因此与正常情况有所不同。这是一个示例：

1 Matt
00:00:00,100 --> 00:00:01,500
This is said by Matt

2 Lucas
00:00:01,700 --> 00:00:02,300
While this is said by Lucas

我想做的是解析这些文件，以创建data.frame如下：

+---------------------------------------------+
| CHARACTER    |  TEXT                        |
|--------------+------------------------------|
| Matt         |  This is said by Matt        | 
|--------------+------------------------------|
| Lucas        |  While this is said by Lucas |
+---------------------------------------------+

因此，我不想要字幕的数字或分钟。 我已经能够使用readText库读取文本，从而导致这样的内容：

1 Matt\n00:00:00,100 --> 00:00:01,500\nThis is said by Matt.\n\n2 Lucas\n00:00:01,700 --> 00:00:02,300\nWhile this is said by Lucas

请注意，文本内部也可能有\ n其他（可读）的字符

是我被卡住的地方，我想我必须使用某种REGEX来提取所有名称，然后是所有文本，但是我对如何执行此操作一无所知。

任何帮助都非常感谢！

Answer 1

这是一个无需正直的逐步完成的方法。它有点草率，但它可以显示有关如何处理这样的文件的逻辑。最终结果是一个数据框架，您可以在其中获取所需的信息。

txt <- "1 Matt
00:00:00,100 --> 00:00:01,500
This is said by Matt

2 Lucas
00:00:01,700 --> 00:00:02,300
While this is said by Lucas\nand another line

3
00:00:01,700 --> 00:00:02,300
While this is said by nobody"

library(readr)
library(tidyr)
library(tibble)
library(dplyr)
library(purrr)

df <- tibble(txt = read_lines(txt))

df %>% 
  rowid_to_column("row") %>% 
  group_by(group = cumsum(txt == "")) %>% 
  filter(!(txt == "")) %>% 
  mutate(field = pmin(row_number(), 3)) %>% 
  group_by(group, field) %>% 
  summarize(txt = paste(txt, collapse = "\n"), .groups = "drop") %>% 
  pivot_wider(names_from = "field",
              values_from = "txt") %>% 
  select(-group) %>% 
  set_names(c("Col1", "Col2", "Col3")) %>% 
  separate(Col1, c("Col1A", "Col1B"), extra = "merge", fill = "right")

然后您将获得此数据框架。当然，您可以将任何东西命名。

# A tibble: 3 x 4
  Col1A Col1B Col2                          Col3                                           
  <chr> <chr> <chr>                         <chr>                                          
1 1     Matt  00:00:00,100 --> 00:00:01,500 "This is said by Matt"                         
2 2     Lucas 00:00:01,700 --> 00:00:02,300 "While this is said by Lucas\nand another line"
3 3     NA    00:00:01,700 --> 00:00:02,300 "While this is said by nobody"

---

在这里编辑

是一种使用一些整理的更简化的方式。

library(tidyr)
library(dplyr)

tibble(txt = txt) %>% 
  separate_rows(txt, sep = "\\n\\n") %>% 
  separate(txt, c("A", "B", "C"), sep = "\n", extra = "merge") %>% 
  separate(A, c("A1", "B2"), extra = "merge", fill = "right")

Answer 2

您是对的，可以使用正则表达式来实现这一目标。使用Stringr软件包通常是一个好主意。这在很大程度上取决于您的文本的一致性，但这对您的示例有用。如果规则有例外，它可能行不通，但是您可以调整模式。使用 Regex101 是一个很好的帮助。

在您的反馈之后，我认为首先使用strsplit将文本拆分为块。然后使用dplyr和Stringr：

library(dplyr)

input_string <- "1 Matt\n00:00:00,100 --> 00:00:01,500\nThis is said by Matt.\n\n
                 2 Lucas\n00:00:01,700 --> 00:00:02,300\nWhile this is said by Lucas:\n Hi I'm Lucas\n Lucas is my name\n\n
                 1237 VvdL\n00:00:02,701 --> 00:00:02,900\nI'm\nHappy\nThis\nSeems\nTo\nWork"

tmp <- strsplit(input_string, split = '\\n\\n', perl = T) %>%
  data.frame 

colnames(tmp) <- "full_line"

tmp %>%
  mutate(CHARACTER = stringr::str_extract_all(full_line, "(?<=\\d )[a-zA-Z]+?(?=\\n)"), 
         TEXT = stringr::str_extract_all(full_line, "(?<=\\d\\n)(.|\\s)*")) %>%
  select(CHARACTER, TEXT)


 CHARACTER                                                           TEXT
1      Matt                                          This is said by Matt.
2     Lucas While this is said by Lucas:\n Hi I'm Lucas\n Lucas is my name
3      VvdL                              I'm\nHappy\nThis\nSeems\nTo\nWork