X1     X2     X3      X4   X5  X6   X7  X8     Y1     Y2
0  0.98  514.5  294.0  110.25  7.0   2  0.0   0  15.55  21.33
1  0.98  514.5  294.0  110.25  7.0   3  0.0   0  15.55  21.33
2  0.98  514.5  294.0  110.25  7.0   4  0.0   0  15.55  21.33
3  0.98  514.5  294.0  110.25  7.0   5  0.0   0  15.55  21.33
4  0.90  563.5  318.5  122.50  7.0   2  0.0   0  20.84  28.28

data = pd.read_excel("ENB2012_data.xlsx")
print(data.head())
data = data[["X1", "X2", "X3", "X4", "X5", "X6", "X7", "X8"]]
predict = "Y1"
X = np.array(data.drop([predict], 1)) #the error lies on this line.
Y = np.array(data[predict])

Error message: KeyError: "['Y1'] not found in axis"