Pyhton实用教程-第10章-集合与概率PPT课件

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10.1 理解Python中的集合类型
输出： 5 kinds of fruit were bought in two days, Its variety has {'pear', 'apple', 'strawberry', 'banana', 'cherry'} 1 kinds of the same fruit were bought in two days, Its variety has {'apple'} The first day of the purchase of fruit are:{'pear', 'strawberry', 'banana'} The second day of the purchase of fruit are:{'cherry'}
11: print("The first day of the purchase of fruit are:{0}".format(first_day_diff_food))
12: print("The second day of the purchase of fruit are:{0}".format(second_day_diff_food))
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10.1 理解Python中的集合类型
程序 10.1 食堂进购水果案例
1: first_day_food = set(['apple', 'strawberry', 'banana', 'pear'])
2: second_day_food = set()
3: second_day_food.add('apple')
分别调用集合的union、intersection
.format(len(union_food), union_food)) 7: the_same_food = first_day_food.intersection(second_day_food) 8: print("{0} kinds of the same fruit were bought in two days, there are {1}"
4:mpl.rcParams['font.sans-serif']=[u'simHei']
5:mpl概.rcP率aram的s[两'axe大s.un概ico型de_：minus']=False
是6:nu一m•be种rS古iz描e典= 2述0概0 当型试验次数很大时所呈现的概率性质的定律。
7:randData = np.random.normal(scale=100, size=numberSize)
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10.2 概率基础知识
概率问题举例：
程序 10.3 基因组合
1: import itertools
2: parents_gene = ["F", "f", "F", "f"]
和difference函数，求取集合的并集， 交集与差集
.format(len(源自文库he_same_food), the_same_food))
9: first_day_diff_food = first_day_food.difference(second_day_food)
10: second_day_diff_food = second_day_food.difference(first_day_food)
4: second_day_food.add('cherry')
5: union_food = first_day_food.union(second_day_food) 6: print("{0} kinds of fruit were bought in two days, there are {1}"
在8:ra随nd•D机ata几_事av何er件ag概e =的型[] 大量重复出现中，往往呈现几乎必然的规律。
9:randData_sum = 0 10:for index in range(len(randData)):
randData_average.append((randData[index] + randData_sum) / (index + 1.0)) 11:x = np.arange(0,numberSize,1) 12:y = randData_average 13:plt.title('大数定律') 14:plt.xlabel('数据量') 15:plt.ylabel('平均值') 16:plt.plot(x,y) 17:plt.plot([0,numberSize], [0,0], 'r') 18:plt.show()
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10.1 理解Python中的集合类型
P集yt合ho的n 创set建是、基添本加数、据删类除型、的交一集种、集并合集类、型差，集它等与实数用学操上作的。集合概念相同。
以学校食堂每天进购水果的品种构成的集合为例，假设第一天购买水果的品种为 Python中集合 苹果、草莓、香蕉、梨，第二天购买的品种为苹果、樱桃，那么请问： • 可变集合(set) ①两天共买过多少样水果，其品种有哪些？ • 不可变集合(frozenset) ②两天所买相同水果的品种有哪些？ ③两天中单独购买的水果的品种又有哪些？
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人工智能及其实践教程
主编：丁亮 姜春茂
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第10章 集合与概率
10.1 理解Python中的集合类型 10.2 概率基础知识 10.3 贝叶斯分类 10.4 案例：线上课程分类 10.5 总结
➢ 熟练使用python中关于集合的操作 ➢ 了解概率的应用实例 ➢ 理解基于概率的朴素贝叶斯算法
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10.2 概率基础知识
程序 10.2 基因组合
1:imp概ort n率um亦py 称as n“p或然率”、“机率”。它反映随机事件出现的可能性大小的量度。
2:import matplotlib as mpl
大数定律： 3:import matplotlib.pyplot as plt