Filter out rows based on list of strings in Pandas
Had a similar question, found this old thread, I think there are other ways to get the same result. My issue with @EdChum's solution for my particular application is that I don't have a list that will be matched exactly. If you have the same issue, .isin
isn't meant for that application.
Instead, you can also try a few options, including a numpy.where:
removelist = ['ayside','rrowview']
df['flagCol'] = numpy.where(df.stn.str.contains('|'.join(remove_list)),1,0)
Note that this solution doesn't actually remove the matching rows, just flags them. You can copy/slice/drop as you like.
This solution would be useful in the case that you don't know, for example, if the station names are capitalized or not and don't want to go through standardizing text beforehand. numpy.where
is usually pretty fast as well, probably not much different from .isin
.
Use isin:
cleaned = df[~df['stn'].isin(remove_list)]
In [7]:
remove_list = ['Arbutus','Bayside']
df[~df['stn'].isin(remove_list)]
Out[7]:
stn years_of_data total_minutes avg_daily \
date
1900-01-14 AlberniElementary 4 5745 34.1
1900-01-14 AlberniWeather 6 7129 29.5
1900-01-14 Arrowview 7 10080 27.6
TOA_daily K_daily
date
1900-01-14 114.6 0.298
1900-01-14 114.6 0.257
1900-01-14 114.6 0.241