将strsplit的结果分配给数据框的多列 [英] Assigning results of strsplit to multiple columns of data frame

问题描述

我正在尝试将一个字符向量在一个数据帧内分成三个不同的向量.

I am trying to split a character vector into three different vectors, inside a data frame.

我的数据如下:

> df <- data.frame(filename = c("Author1 (2010) Title of paper", 
                                "Author2 et al (2009) Title of paper",
                                "Author3 & Author4 (2004) Title of paper"),
                   stringsAsFactors = FALSE)

我想将这3个信息(authors，year，title)分成三个不同的列，这样就可以了:

And I would like to split those 3 informations (authors, year, title) into three different columns, so that it would be:

> df
                          filename             author  year   title
 1           Author1 (2010) Title1            Author1  2010  Title1
 2     Author2 et al (2009) Title2      Author2 et al  2009  Title2
 3 Author3 & Author4 (2004) Title3  Author3 & Author4  2004  Title3

我已经使用strsplit将每个filename拆分为3个元素的向量:

I have used strsplit to split each filename in a vector of 3 elements:

 df$temp <- strsplit(df$filename, " \\(|\\) ")

但是现在，我找不到将每个元素放在单独列中的方法.我可以访问像这样的特定信息:

But now, I can't find a way to put each element in a separate column. I can access a specific information like that:

> df$temp[[2]][1]
[1] "Author2 et al"

但找不到如何将其放在其他列中

but can't find how to put it in the other columns

> df$author <- df$temp[[]][1]
Error

推荐答案

使用tidyr软件包，这是一个separate解决方案:

With the tidyr package, here's a separate solution:

separate(df, "filename", c("Author","Year","Title"), sep=" \\(|\\) "), remove=F)
#                                  filename            Author
# 1           Author1 (2010) Title of paper           Author1
# 2     Author2 et al (2009) Title of paper     Author2 et al
# 3 Author3 & Author4 (2004) Title of paper Author3 & Author4
#   Year          Title
# 1 2010 Title of paper
# 2 2009 Title of paper
# 3 2004 Title of paper

前导空格和尾随空格已被考虑

Leading and trailing spaces have been accounted for

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