Use gsub remove all string before first white space in R

问题

I have a data frame like this:

name         weight
r apple         0.5
y pear          0.4
y cherry        0.1
g watermelon    5.0
pp grape        0.5
y apple pear    0.4
...  ...

I would like to remove all characters before the first white space in the name column. Can anybody give me a favor? Thank you!

回答1:

Try this:

sub(".*? ", "", D$name)

Edit:

The pattern is looking for any character zero or more times (.*) up until the first space, and then capturing the one or more characters ((.+)) after that first space. The ? after .* makes it "lazy" rather than "greedy" and is what makes it stop at the first space found. So, the .*? matches everything before the first space, the space matches the first space found.

回答2:

If D is your data frame, try

sub(".+? ", "", D$name)

回答3:

Let's say your data frame is called 'df'

library(reshape2)    
df$name = colsplit(df$name," ", names = c("chuck","name"))[,2]

来源：https://stackoverflow.com/questions/32767164/use-gsub-remove-all-string-before-first-white-space-in-r