Column order in pandas.concat

Question

I do as below:

data1 = pd.DataFrame({ \'b\' : [1, 1, 1], \'a\' : [2, 2, 2]})
data2 = pd.DataFrame({ \'b\' : [1, 1, 1], \'a\' : [2, 2, 2]})
frames = [data1, data2         


        

Answer 1

def concat_ordered_columns(frames):
    columns_ordered = []
    for frame in frames:
        columns_ordered.extend(x for x in frame.columns if x not in columns_ordered)
    final_df = pd.concat(frames)    
    return final_df[columns_ordered]       

# Usage
dfs = [df_a,df_b,df_c]
full_df = concat_ordered_columns(dfs)

This should work.