将一个数据帧拆分为几个数据帧 [英] Splitting a dataframe into several dataframes

问题描述

我有一个数据框，需要根据正则表达式搜索将其分为几个数据框。搜索没有固定的模式，即有时只有一个正则表达式，有时是多个正则表达式的组合。这是一个仅提取了一组行的最小示例：

I have a dataframe that I need split into several dataframes, based on regex searches. There is no set pattern to the searches, i.e. sometimes there is a single regex, sometime a combination of several. Here is a minimal example with just one set of rows extracted:

Name <- c("John", "Jane", "Arthur", "Maggie")
Age <- c(20, 30, 31, 33)
City <- c("London", "Paris", "New York", "Delhi")

main_df <- data.frame(Name, Age, City)

sub_df <- main_df %>% 
  filter(grepl("J", Name))

main_df <- main_df %>% 
  filter(!grepl("J", Name))

请注意，我正在将一些行提取到新的数据框中，然后从主数据框中删除提取的行。

Note that I am extracting some rows into a new dataframe, then deleting the extracted rows from the main dataframe.

我正在寻找一个单行命令来执行此操作。帮助表示赞赏，尤其是在使用 dplyr 的情况下。

I am looking for a single line command to do this. Help appreciated, especially if using dplyr.

推荐答案

我们可以编写一个函数，如

We can write a function like

split_df <- function(df, char) {
  split(df, grepl(char, df$Name))
}

new_df <- split_df(main_df, "J")

new_df[[1]]
#    Name Age     City
#3 Arthur  31 New York
#4 Maggie  33    Delhi

new_df[[2]]
#  Name Age   City
#1 John  20 London
#2 Jane  30  Paris

代替 char 确保传递适当的字符以进行分割。您还可以对 char 使用正则表达式，例如 ^ J （以J开头）或 J $ （以J结尾）等。

In place of char make sure to pass appropriate character to split on. You can also use regex for char like ^J (starts with J) or J$ (ends with J) etc.

例如

new_df <- split_df(main_df, "^J")

与上面的输出相同。

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