I tried to concatenate the two columns firstname and lastname into one columns. Now, how about to split it into two columns when his/her firstname consisting of 2, 3 and more words from his/her lastname? Is there any easy way to do it? I tried using str.split() methods. But it says "columns should be the same length."

CodePudding user response：

We can use str.extract here:

df[["firstname", "lastname"]] = df["fullname"].str.extract(r'^(\w (?: \w )*) (\w )$')

The regex pattern used above assigns as many name words from the start as possible, leaving only the final component for the last name. Here is a formal explanation of the regex:

• ^ from the start of the name
  • ( open first capture group \1
    • \w match the first word
    • (?: \w )* then match space and another word, together zero or more times
  • ) close first capture group
  • match a single space
  • (\w ) match and capture the last word as the last name in \2
• $ end of the name