行处理——运算

基于pandas

• 求和。

column_list = ['Fiber_TD_(g)', 'Sugar_Tot_(g)']
# Let's sum up the total amount of fiber and sugar across all the foods.
total = food_info[column_list].sum(axis=0)
# result has two values, one is the taotal fiber of all foods, the other is the total sugar of all foods

 输入：dataframe，输出：行vector，包含若干求和后数值。