First, sort the DataFrame and then all you need is groupby.diff() : df = df.sort_values(by=['site', 'country', 'date']) df['diff'] ... ... <看更多>

Discard data that belongs to groups with only a few members. Filter out data based on the group sum or mean. Some combination of the above: GroupBy will examine ... ... <看更多>

from pandas.core.groupby.indexing import GroupByIndexingMixin. from pandas.core.indexes.api ... aggregate : Apply aggregate function to the GroupBy object. ... <看更多>