[R] Counting enumerated items in each element of a character vector

[Boris Steipe]

How about:

unlist(lapply(strsplit(text1, "Example"), function(x) { length(x) - 1 } ))


Splitting your string on the five "Examples" in each gives six elements. length(x) - 1 is the number of
matches. You can use any regex instead of "example" if you need to tweak what you are looking for.


B.




> On Apr 25, 2017, at 8:14 PM, Dan Abner <dan.abner99 at gmail.com> wrote:
> 
> Hi all,
> 
> I am looking for a streamlined way of counting the number of enumerated
> items are each element of a character vector. For example:
> 
> 
> text1<-c("This is an example.
> List 1
> 1) Example 1
> 2) Example 2
> 10) Example 10
> List 2
> 1) Example 1
> 2) Example 2
> These have been examples.","This is another example.
> List 1
> 1. Example 1
> 2. Example 2
> 10. Example 10
> List 2
> 1. Example 1
> 2. Example 2
> These have been examples.","This is a third example. List 1 1) Example 1.
> 2) Example 2. 10) Example 10. List 2 1) Example 1. 2) Example 2. These have
> been examples."
> ,"This is a fourth example. List 1 1. Example 1. 2. Example 2. 10. Example
> 10. List 2 Example 1. 2. Example 2. These have been examples.")
> 
> text1
> 
> ===
> 
> I would like the result to be c(5,5,5,5). Notice that sometimes there are
> leading hard returns, other times not. Sometimes are there separate lists
> and the same numbers are used in the enumerated items multiple times within
> each character string. Sometimes the leading numbers for the enumerated
> items exceed single digits. Notice that the delimiter may be ) or a period
> (.). If the delimiter is a period and there are hard returns (example 2),
> then I expect that will be easy enough to differentiate sentences ending
> with a number from enumerated items. However, I imagine it would be much
> more difficult to differentiate the two for example 4.
> 
> Any suggestions are appreciated.
> 
> Best,
> 
> Dan
> 
> 	[[alternative HTML version deleted]]
> 
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