问题
i have the flowing text string:
string <- "['CBOE SHORT-TERM VIX FUTURE DEC 2016', 81.64],\n\n ['CBOE SHORT-TERM VIX FUTURE JAN 2017', 18.36]"
is there a simple way of extracting numerical elements from text without having to use:
string_table <- strsplit(string, " ")
and then select n-th element and continue to strsplit until i have what i need.
the result should be:
result <- c(2016, 81, 64, 2017, 18, 36)
thank you.
回答1:
We can use str_extract_all by specifying the pattern as one or more number ([0-9]+). The output will be a list of length 1, extract the vector with [[ and convert to numeric.
library(stringr)
as.numeric(str_extract_all(string, "[0-9]+")[[1]])
#[1] 2016 81 64 2017 18 36
If we are using strsplit, split by the non-numeric characters
as.numeric(strsplit(string, "\\D+")[[1]][-1])
#[1] 2016 81 64 2017 18 36
来源：https://stackoverflow.com/questions/40744463/how-to-extract-numbers-from-text