[FIXED] How to stack columns/series vertically in pandas

Issue

I currently have a dataframe that looks something like this

entry_1      entry_2
2022-01-21   2022-02-01
2022-03-23   NaT
2022-04-13   2022-06-06

however I need to vertically stack my two columns to get something like this

entry
2022-01-21
2022-03-23
2022-04-13
2022-02-01
NaT
2022-06-06

I've tried using df['entry'] = df['entry_1].append(df['entry_2']).reset_index(drop=True) to no success

Solution

I recommend that you use

pd.DataFrame(df.values.ravel(), columns=['all_entries'])

This will allow you to return the flattened underlying data as an ndarray. By wrapping that in pd.Dataframe() you will convert it back to a dataframe with the column name "all_entries"

For more information please visit the pandas doc: https://pandas.pydata.org/docs/reference/api/pandas.Series.ravel.html

Answered By - Eduardo Alvarez