有时候需要对 pandas Series 里的值进行一些操作,但是没有内置函数,这时候可以自己写一个函数,使用 pandas Series 的 apply 方法,可以对里面的每个值都调用这个函数,然后返回一个新的 Series
import pandas as pd s = pd.Series([1, 2, 3, 4, 5]) def add_one(x): return x + 1 print s.apply(add_one) # 结果: 0 2 1 3 2 4 3 5 4 6 dtype: int64
一个栗子:
names = pd.Series([ ‘Andre Agassi‘, ‘Barry Bonds‘, ‘Christopher Columbus‘, ‘Daniel Defoe‘, ‘Emilio Estevez‘, ‘Fred Flintstone‘, ‘Greta Garbo‘, ‘Humbert Humbert‘, ‘Ivan Ilych‘, ‘James Joyce‘, ‘Keira Knightley‘, ‘Lois Lane‘, ‘Mike Myers‘, ‘Nick Nolte‘, ‘Ozzy Osbourne‘, ‘Pablo Picasso‘, ‘Quirinus Quirrell‘, ‘Rachael Ray‘, ‘Susan Sarandon‘, ‘Tina Turner‘, ‘Ugueth Urbina‘, ‘Vince Vaughn‘, ‘Woodrow Wilson‘, ‘Yoji Yamada‘, ‘Zinedine Zidane‘ ])
把以上Series里的名字从"Firstname Lastname" 转换成 "Lastname, FirstName"
可以使用apply方法:
def reverse_name(name): name_array = name.split(‘ ‘) new_name = ‘{}, {}‘.format(name_array[1],name_array[0]) return new_name print(names.apply(reverse_name))
0 Agassi, Andre 1 Bonds, Barry 2 Columbus, Christopher 3 Defoe, Daniel 4 Estevez, Emilio 5 Flintstone, Fred 6 Garbo, Greta 7 Humbert, Humbert 8 Ilych, Ivan 9 Joyce, James 10 Knightley, Keira 11 Lane, Lois 12 Myers, Mike 13 Nolte, Nick 14 Osbourne, Ozzy 15 Picasso, Pablo 16 Quirrell, Quirinus 17 Ray, Rachael 18 Sarandon, Susan 19 Turner, Tina 20 Urbina, Ugueth 21 Vaughn, Vince 22 Wilson, Woodrow 23 Yamada, Yoji 24 Zidane, Zinedine dtype: object
原文：https://www.cnblogs.com/liulangmao/p/9231804.html