将一系列转换应用于pandas DataFrame对象

Question

I am relatively new to Python programming. I have a pandas DataFrame object say obj1. I need to apply a series of transformation to records stored in obj1['key']. Suppose obj1['key'] has 300 entries and I need to apply func1 then func2 then func3 on each of the 300 entries and store the final result in obj1['key']. One way would be to do as below. Is there a better way to do the same?

obj1['key']=[func3(func2(func1(item))) for item in obj1['key']]

Python generators can't be used for this purpose right.

Answer 1

是的，您可以使用默认方法DataFrame.apply（）

df = df.apply(f1).apply(f2).apply(fn)

Answer 2

define a function

def recursivator(x, fs):
    return recursivator(fs[-1](x), fs[:-1]) if len(fs) > 0 else x

x is the thing being operated on, fs is a list of functions.

df = df.applymap(lambda x: recursivator(x, fs))