pandas - Array length does not match index length -

i'm looking combine few time series varying dates single dataframe.

each time series' column names date , px

i've created date index dates , tried combine time series doing:

dates = pd.date_range('01/01/2017', periods=12, freq='m')

df = pd.dataframe({    'date': dates,    'a': df2['px'],    'b': df3['px']    .    .    etc }) 

expected output:

      date                    b           c           d           e 2017-01-31    -0.4579         nan           .           .           . 2017-02-28     0.5787         nan           .           .           . 2017-03-31    -2.2319     -1.0244         etc         etc         etc 2017-04-30    -2.0713     -2.1069 2017-05-31        nan      2.0158 2017-06-30        nan      1.0541 2017-07-31        nan      1.8901 2017-08-31        nan         nan 2017-09-30        nan         nan . . etc 

iiuc:

dfs = [df1,df2,df3] pd.concat([df.set_index('date') df in dfs], axis=1).reset_index()