Handling Concat and Shift Feature in Pandas for Data Science [on hold]

I am trying to USE Lag features AND Concat() and Shift() function,
    seies = Series.from_csv('sugar_price_2.csv', header=0, sep=';')

    In [25]: prices = DataFrame(series.values)

    In [26]: dataframe = concat([prices.shift(3), prices.shift(2), prices.shift(1), prices], axis=1)

    In [27]: dataframe.coloumns = ['t-2', 't-1', 't', 't+1']

    In [28]: print(dataframe.head(20))

       0       0       0     0     
0      NaN     NaN     NaN  2800
1      NaN     NaN  2800.0  2800
2      NaN  2800.0  2800.0  2800
3   2800.0  2800.0  2800.0  2800
4   2800.0  2800.0  2800.0  2800
5   2800.0  2800.0  2800.0  2800
But The 't-2', 't-1', 't' Coloumn names aren't showing up .
Can anyone say what's wrong in my code...