Answers for "pandas order according to list"

Python sort dataframe by list

# sorts the dataframe so resulting order of ColumnName matches order in list
df = df.set_index(ColumnName).reindex(list_to_sort_by).reset_index()

pandas order dataframe by column of other dataframe

df1 = df1.set_index('column_in_df1')
df1 = df1.reindex(index=df2['column_in_df2'])
df1 = df1.reset_index()