Replace multiple strings in one gsub() or chartr() statement in R?

r string gsub
Eric Chang picture Eric Chang · Nov 27, 2015 · Viewed 41.5k times · Source

I have a string variable containing alphabet[a-z], space[ ], and apostrophe['],eg. x <- "a'b c" I want to replace apostrophe['] with blank[], and replace space[ ] with underscore[_].

x <- gsub("'", "", x)
x <- gsub(" ", "_", x)

It works absolutely, but when I have a lot of condition, the code becomes ugly. Therefore, I want to use chartr(), but chartr() can't deal with blank, eg.

x <- chartr("' ", "_", x) 
#Error in chartr("' ", "_", "a'b c") : 'old' is longer than 'new'

Is there any way to solve this problem? thanks!

Answer

Ronak Shah picture Ronak Shah · Nov 27, 2015

You can use gsubfn

library(gsubfn)
gsubfn(".", list("'" = "", " " = "_"), x)
# [1] "ab_c"

Similarly, we can also use mgsub which allows multiple replacement with multiple pattern to search

mgsub::mgsub(x, c("'", " "), c("", "_"))
#[1] "ab_c"

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