This is my original CSV file enter image description here

I want to make the genre column only the first tag. when I use

dataframe['genre'] = dataframe['genre'].str.extract('^(. ?),')

it gets the string before the first comma but it also gets rid of columns without commas

enter image description here

how can I make it keep the ones without commas as well?

CodePudding user response：

Use a different regex:

dataframe['genre'] = dataframe['genre'].str.extract('^([^,] )')

Regex:

^       # match start of line
([^,] ) # capture everything but comma

CodePudding user response：

Close, but it's easier to split the strings than develop a regex in this case, because it's so simple. You can do this instead.

dataframe['genre'] = dataframe['genre'].str.split(',').str[0]