Basic Concepts Probability concepts Terms Random variable A quantity whose possible values are uncertain.Outcomes The possible values of a random variable.Event A specified set of outcomes. Properties 0 < P(E) <1 Events Odds (赔率) Odds for the eve…
Chaper Objectives (章节目标) In this chapter you will learn: (在这一章节中,你将学习) 1. Some common uses of database systems. (数据库系统的一些普通扩法) 2.The characteristics of file-based systems. (基于文件系统的一些…
_init_() takes 4 positional arguments but 5 were given
源代码是这样
class people:name age 0__weight 0def __init__(self, n, a ,w):self.name nself.age aself.weight wdef speak(self):print("hello, Im {}, Im {} years old".format(self.name, sel…