我被一个简单的问题困住了在函数中使用choice时，似乎所有函数都被执行，而只有一个函数应该被执行。2例如：

from ordereddict import OrderedDict
from random import choice

def PrintStrings():
    Text = choice(["Gutentag!", "Ni hao!", "Hola!"])
    print "Chosen Text is:", Text
    return Text

class Greeting():
    fields = OrderedDict([
         ("Morning",     "Hi"),
         ("Afternoon",   "Good Afternoon!"),
         ("Evening",     "Good Evening!"),
    ])

    def change(self):
        self.fields["Morning"] = "Good morning!"

    def changerandom(self, n = 1): 
        function=[
                    {self.fields["Morning"]: PrintStrings()},
                    {self.fields["Afternoon"]: PrintStrings()},
                    {self.fields["Evening"]: PrintStrings()},
                 ]
        result = {}
        for i in range(n):
            result.update(choice(function))
            print "Updated string:",result
            return result

text = Greeting()
text.change()
text.changerandom()

运行此脚本时，我将获得所有3个

{self.fields["Morning"]: PrintStrings()},
                    {self.fields["Afternoon"]: PrintStrings()},
                    {self.fields["Evening"]: PrintStrings()},

执行，而不应该执行。此脚本返回：

Chosen Text is: Ni hao!
Chosen Text is: Gutentag!
Chosen Text is: Hola!
Updated string: {'Good morning!': 'Hola!'}

预期结果为：

Chosen Text is: Hola!
Updated string: {'Good morning!': 'Hola!'}