splitting column in R - r

Question

I'm facing the following problem. I've got a table with a column called title.
The title column contains rows with values like To kill a mockingbird (1960).
So basically the format of the column is [title] ([year]). What I need are two columns: title and year, year without brackets.
One other problem is that some rows contain a title including brackets. But
basically the last 6 characters of every row are year wrapped in brackets.
How do I create the two columns, title and year?
What I have is:
Books$title <- c("To kill a mockingbird (1960)", "Harry Potter and the order of the phoenix (2003)", "Of mice and men (something something) (1937)")
title
To kill a mockingbird (1960)
Harry Potter and the order of the phoenix (2003)
Of mice and men (something something) (1937)
What I need is:
Books$title <- c("To kill a mockingbird", "Harry Potter and the order of the phoenix", "Of mice and men (something something)")
Book$year <- c("1960", "2003", "1937")
title year
To kill a mockingbird 1960
Harry Potter and the order of the phoenix 2003
Of mice and men (something something) 1937

Answer 1

We can work around substring the last 6 characters.
First we recreate your data.frame:
df <- read.table(h=T, sep="\n", stringsAsFactors = FALSE,
text="
Title
To kill a mockingbird (1960)
Harry Potter and the order of the phoenix (2003)
Of mice and men (something something) (1937)")
Then we create a new one. The first column, Title is everything from df$Title but the last 7 characters (we also remove the trailing space). The second column, Year is the last 6 characters from df$Title and we remove any space, opening or closing bracket. (gsub("[[:punct:]]", ...) would have worked as well.
data.frame(Title=substr(df$Title, 1, nchar(df$Title)-7),
Year=gsub(" |\\(|\\)", "", substr(df$Title, nchar(df$Title)-6, nchar(df$Title))))
Title Year
1 To kill a mockingbird 1960
2 Harry Potter and the order of the phoenix 2003
3 Of mice and men (something something) 1937
Does that solve your problem?

Answer 2

try to use substrRight(df$Title, 6) in a loop to extract last 6 characters so the year with brackets and save it as new column
Extracting the last n characters from a string in R

Answer 3

Similar to #Vincent Bonhomme:
I assumue that the data are in some text file that I have called so.dat from where I read the data into a data.frame that also contains two columns for the title and year to be extracted. Then I use substr() to separate title from the fixed length year at the end, leaving the () alone as the OP apparently wants them:
titles <- data.frame( orig = readLines( "so.dat" ),
text = "", yr = "", stringsAsFactors = FALSE )
titles$text <- substring( titles[ , 1 ],
1, nchar( titles[ , 1 ] ) - 7 )
titles$yr <- substring( titles[ , 1 ],
nchar( titles[ , 1 ] ) - 5, nchar( titles[ , 1 ] ) )
The original data can be removed or not, dpending upon further need.