Time Series Analysis to find a particular date based on conditions

Question

I have the following dataframe badges . The Class column has the level of the badge (1=Gold, 2=Silver, 3=Bronze) . I want to get the time when the user with UserId = '699' got his first silver medal. I tried the given code but I am getting a KeyError. Please help me fix this.

DataFrame

   Id | UserId |  Name          |        Date              |Class | TagBased
   2  | 23     | Autobiographer | 2016-01-12T18:44:49.267  |   3  | False
   3  | 22     | Autobiographer | 2016-01-12T18:44:49.267  |   3  | False
   4  | 21     | Autobiographer | 2016-01-12T18:44:49.267  |   3  | False
   5  | 20     | Autobiographer | 2016-01-12T18:44:49.267  |   3  | False
   6  | 19     | Autobiographer | 2016-01-12T18:44:49.267  |   3  | False

Code

test_silver = badges[badges.Date.loc[badges.UserId=='699']]
min(test_silver)

Answer 1

You can use boolean indexing (like you already did) and then head to extract the first record:

badges.loc[badges.UserId.eq('699') & badges.Class.eq(2), 'Date'].head(1)