Remove all text before colon

Question

I have a file containing a certain number of lines. Each line looks like this:

TF_list_to_test10004/Nus_k0.345_t0.1_         


        

Answer 1

A simple regular expression used with gsub():

x <- "TF_list_to_test10004/Nus_k0.345_t0.1_e0.1.adj:PKMYT1"
gsub(".*:", "", x)
"PKMYT1"

See ?regex or ?gsub for more help.

Answer 2

You can use awk like this:

awk -F: '{print $2}' /your/file

Answer 3

Some very simple move that I missed from the best response @Sacha Epskamp was to use the sub function, in this case to take everything before the ":"(instead of removing it), so it was very simple:

foo <- "TF_list_to_test10004/Nus_k0.345_t0.1_e0.1.adj:PKMYT1"

# 1st, as she did to remove all before and up to ":":
gsub(".*:","",foo)

# 2nd, to keep everything before and up to ":": 
gsub(":.*","",foo)

Basically, the same thing, just change the ":" position inside the sub argument. Hope it will help.

Answer 4

Below are 2 equivalent solutions:

The first uses perl's -a autosplit feature to split each line into fields using :, populate the F fields array, and print the 2nd field $F[1] (counted starting from field 0)

perl -F: -lane 'print $F[1]' file

The second uses a regular expression to substitute s/// from ^ the beginning of the line, .*: any characters ending with a colon, with nothing

perl -pe 's/^.*://' file

Answer 5

There are certainly more than 2 ways in R. Here's another.

unlist(lapply(strsplit(foo, ':', fixed = TRUE), '[', 2))

If the string has a constant length I imagine substr would be faster than this or regex methods.

Answer 6

I was working on a similar issue. John's and Josh O'Brien's advice did the trick. I started with this tibble:

library(dplyr)
my_tibble <- tibble(Col1=c("ABC:Content","BCDE:MoreContent","FG:Conent:with:colons"))

It looks like:

  | Col1 
1 | ABC:Content 
2 | BCDE:MoreContent 
3 | FG:Content:with:colons

I needed to create this tibble:

  | Col1                  | Col2 | Col3 
1 | ABC:Content           | ABC  | Content 
2 | BCDE:MoreContent      | BCDE | MoreContent 
3 | FG:Content:with:colons| FG   | Content:with:colons

And did so with this code (R version 3.4.2).

my_tibble2 <- mutate(my_tibble
        ,Col2 = unlist(lapply(strsplit(Col1, ':',fixed = TRUE), '[', 1))
        ,Col3 = gsub("^[^:]*:", "", Col1))