Filtering pandas dataframe rows by contains str

Question

I have a python pandas dataframe df with a lot of rows. From those rows, I want to slice out and only use the rows that contain the word \'ball\' in the \'body

Answer 1

You could either use .str again to get access to the string methods, or (better, IMHO) use case=False to guarantee case insensitivity:

>>> df = pd.DataFrame({"body": ["ball", "red BALL", "round sphere"]})
>>> df[df["body"].str.contains("ball")]
   body
0  ball
>>> df[df["body"].str.lower().str.contains("ball")]
       body
0      ball
1  red BALL
>>> df[df["body"].str.contains("ball", case=False)]
       body
0      ball
1  red BALL
>>> df[df["body"].str.contains("ball", case=True)]
   body
0  ball

(Note that if you're going to be doing assignments, it's a better habit to use df.loc, to avoid the dreaded SettingWithCopyWarning, but if we're just selecting here it doesn't matter.)

(Note #2: guess I really didn't need to specify 'round' there..)