Python列表、元组、集合与字典小结_set1 in set2什么意思

tuple - 元组 - 只读

my_list = [1,2,3,4,5] # 列表

my_tuple = (1,2,3,4,5) # 元组

my_set = {1,1,2,2,3,3} # 集合

print(my_set) # 集合会去除重复元素

set1 = {1,2,3}
set1.add(4)
set1.add(5)
print(set1)
set2 = {1,3,5,7,9}
set3 = set1.intersection(set2)   # 交集
# 等同于 set3 = set1 & set2
print(set3)
set3 = set1.union(set2)          # 并集
# 等同于 set3 = set1 | set2
print(set3)
set3 = set1.difference(set2)    #差集 ：set1 - set2
# 等同于 set3 = set1 - set2
print(set3)
set3 = set2.difference(set1)    #差集 ： set2 - set1
# 等同于 set3 = set2 - set1
print(set3)
set3 = set1.symmetric_difference(set2)   # 对称差 去掉公共部分人
# 等同于 set3 = set1 ^ set2
print(set3)
for val in set2:
    print(val,end=' ')
print(set2.pop())   # 随机从集合内拿出一个元素
if 3 in set2:
    set2.remove(3)
print(set2)
print(set2.issubset(set1))  #判断set1是否为set2的子集
# 等同于print(set2 > set1)
print(set2.issuperset(set1)) # 判断set1是否为set2的超集
# 等同于print(set1 > set2)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30

例1：列表与元组的应用

def main():
    set4 = {'hello','apple','good','banana','zoo','hello'}
    print(len(set4))
    x = sorted(set4)
    print(x)
    print(type(x))
    list1 = list(set4)
    print(list1)
    list2 = [1,2,3,1,2,4]
    set5 = set(list2)
    print(set5)
    tuple1 = (1,1,2,3,4,4)
    list3 = list(tuple1)
    print(list3)
if __name__ == '__main__':
    main()
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16

小结：列表与元组的转化，一些相关运用。

例2：姓名与成绩

# 方法一、
def main():
    names = ['关羽','张飞','刘备','吕布','貂蝉']
    subjects = ['语文','数学','Python']
    table = []
    for row,name in enumerate(names):
        print('请输入%s的成绩：'%name)
        scores =[]
        table.append(scores)
        for col,subject in enumerate(subjects):
            score = int(input('%s：'%(subject)))
            scores.append(score)
    print(table)


if __name__ == '__main__':
    main()
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17

# 方法二、
def main():
    names = ['关羽','张飞','刘备','吕布','貂蝉']
    subjects = ['语文','数学','Python']
    scores = [[0 for _ in range(3)] for _ in range(5) ]
    print(scores)
    for row,name in enumerate(names):
        print('请输入%s的成绩：'%name)
        for col,subject in enumerate(subjects):
            scores[row][col] = int(input('%s：'%(subject)))
    print(scores)


if __name__ == '__main__':
    main()
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15

例3：# 函数，年，月，日，返回 年月日是这一年的第几天。

# 2018 1 1
# 2016 3 1
# 1980 11 28
# 1981 12 31
def is_leap_year(year):
    return year % 4 ==0 and year % 100 != 0 or year % 400 == 0

def which_day(year,month,date):
    day_of_month = [31,28,31,30,31,30,31,31,30,31,30,31]
    total = 0
    for n in range(month-1):
        total += day_of_month[n]
    if month > 2 and is_leap_year(year):
        total += 1
    return total + date
if __name__ == '__main__':
    main()
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17

字典

def main():
    dict1 = {'name':'xl','age':'20','gender':'sex','hehe':'yoyo'}
    print(dict1['name'])
    dict1['name'] = 'fuck'
    print(dict1)
    dict1.update(h='180', f=['c','h','p','d'])
    print(dict1)
    print(dict1.pop('age'))
    print(dict1.popitem())
    dict1['name'] = None
    del dict1['gender']
    dict1.setdefault('hehe','haha')    #设定默认值，若字典里没有，则显示默认值
    print(dict1['hehe'])
    for x in dict1:                    # 字典遍历
        print(x,'----->',dict1[x])
    dict1.pop('hehe')      # 删除，包括默认值
    print(dict1['hehe'])
if __name__ == '__main__':
    main()
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19

小结：字典的基本运用。