merra_data是dataframe格式，按月份、小时、列进行循环，但是速度较慢，不知道应该如何将for循环代码改进，x'x
for i in range(1,13):
temp1 = merra_data_val[merra_data_val['Month']==i]
temp2 = merra_data[merra_data['Month']==i]
for j in range(0,24):
temp3 = temp1[temp1['Hour']==j]
temp4 = temp2[temp2['Hour']==j]
for k in lable_names_2:
temp3[k] = k_index[i][k][j]*temp4[k]+b_index[i][k][j]
temp1[temp1['Hour']==j] = temp3
print(str(i)+','+str(j))
merra_data_val[merra_data_val['Month']==i] = temp1