在dataframe列中计数元素数

Question

我有一个R数据，在这里，我从一些问卷调查数据导入了CSV文件。

我的专栏之一叫做“新闻方法”(NewsMethods)，在这里，被调查者被要求列出他们获取新闻的方法。数据集中的数据如下所示：

1. 广播；电视；新闻网站(如BBC新闻)；社交媒体网站或应用；口碑
2. 广播；电视；新闻网站(如BBC新闻)；社交媒体网站或应用；口碑
3. 广播；电视；社交媒体网站或应用程序；口碑电视；社交媒体网站或应用程序

..。诸若此类。

我想要做的是用它包含的元素数替换每一列。例如，我想用数字5代替第一个列表。

如果有人对我如何做到这一点有任何想法的话，我将非常感激。提亚

编辑

Radio;Television;News websites (such as BBC News);Social Media websites or apps;Word of mouth
Radio;Television;News websites (such as BBC News);Social Media websites or apps;Word of mouth
Radio;Television;Social Media websites or apps;Word of mouth
Television;Social Media websites or apps
Newspaper;Radio;Television;News websites (such as BBC News)
Television
Radio;Television;Word of mouth
Television;Social Media websites or apps;Word of mouth
Television;Word of mouth
Newspaper;Radio;Television;News websites (such as BBC News);Social Media websites or apps;Word of mouth

我期待这一条改为:5 5 4 2 4 1 3 3 2 6

Answer 1

我们可以使用来自str_count的stringr

library(stringr)
df1$Count <- str_count(df1$NewsMethods, ";")+1
df1$Count
#[1] 5 5 4 2 4 1 3 3 2 6

或者base R选项与regexpr一起使用

lengths(lapply(gregexpr(";", df1$NewsMethods), function(x) x[x>0]) )+1
#[1] 5 5 4 2 4 1 3 3 2 6

数据

df1 <- structure(list(NewsMethods = c('Radio;Television;News websites (such as BBC News);Social Media websites or apps;Word of mouth',
                                  'Radio;Television;News websites (such as BBC News);Social Media websites or apps;Word of mouth',
                                  'Radio;Television;Social Media websites or apps;Word of mouth',
                                  'Television;Social Media websites or apps',
                                  'Newspaper;Radio;Television;News websites (such as BBC News)',
                                  'Television',
                                  'Radio;Television;Word of mouth',
                                  'Television;Social Media websites or apps;Word of mouth',
                                  'Television;Word of mouth',
                                  'Newspaper;Radio;Television;News websites (such as BBC News);Social Media websites or apps;Word of mouth')), 
             .Names = "NewsMethods", row.names = c(NA, -10L), class = "data.frame")

Answer 2

strsplit和lengths组合的R基选择

lengths(strsplit(dfr$NewsMethods, split = ';'))

这意味着：

> lengths(strsplit(dfr$NewsMethods, split = ';'))
 [1] 5 5 4 2 4 1 3 3 2 6

将结果分配给数据文件中的count-variable：

dfr$count <- lengths(strsplit(dfr$NewsMethods, split = ';'))

现在，您的dataframe看起来如下：

> dfr
                                                                                               NewsMethods count
1            Radio;Television;News websites (such as BBC News);Social Media websites or apps;Word of mouth     5
2            Radio;Television;News websites (such as BBC News);Social Media websites or apps;Word of mouth     5
3                                             Radio;Television;Social Media websites or apps;Word of mouth     4
4                                                                 Television;Social Media websites or apps     2
5                                              Newspaper;Radio;Television;News websites (such as BBC News)     4
6                                                                                               Television     1
7                                                                           Radio;Television;Word of mouth     3
8                                                   Television;Social Media websites or apps;Word of mouth     3
9                                                                                 Television;Word of mouth     2
10 Newspaper;Radio;Television;News websites (such as BBC News);Social Media websites or apps;Word of mouth     6

使用的数据：

dfr <- structure(list(NewsMethods = c('Radio;Television;News websites (such as BBC News);Social Media websites or apps;Word of mouth',
                                      'Radio;Television;News websites (such as BBC News);Social Media websites or apps;Word of mouth',
                                      'Radio;Television;Social Media websites or apps;Word of mouth',
                                      'Television;Social Media websites or apps',
                                      'Newspaper;Radio;Television;News websites (such as BBC News)',
                                      'Television',
                                      'Radio;Television;Word of mouth',
                                      'Television;Social Media websites or apps;Word of mouth',
                                      'Television;Word of mouth',
                                      'Newspaper;Radio;Television;News websites (such as BBC News);Social Media websites or apps;Word of mouth')), 
                 .Names = "NewsMethods", row.names = c(NA, -10L), class = "data.frame")