Matching dates between two dataframes in pandas

Question

In Pandas, I have two dataframes, both with dates.

One dataframe contains about 100000 dates and the other about 7000 dates.

How do I keep the dates in dataframe1 that matches the dates with dataframe2?

Answer 1

You can do an inner join operation. Since you only want data that exists in both dataframes.

Since you did not paste much about your code, I will provide a bit of a pseudo-example:

pd.merge(left=df_with_millions, left_on='date_column',
         right=df_with_seven_thousand, right_on='date_column')

You can read more about merging here: http://pandas.pydata.org/pandas-docs/stable/merging.html