[Python知识库]Python基础-5

字典的创建方式
a = {'name':'gaoqi','age':18,'job':'progarammer'}
a
{'name': 'gaoqi', 'age': 18, 'job': 'progarammer'}
字典元素访问
a.get('name')
'gaoqi'
序列解包
a = dict(name='gaoqi',age=18)
a
{'name': 'gaoqi', 'age': 18}
b = [('name','gaoqi'),('age',18)]
b
[('name', 'gaoqi'), ('age', 18)]
k = ['a','b','c']
v = [100,200,300]
d = dict(zip(k,v))
d
{'a': 100, 'b': 200, 'c': 300}

元素添加修改删除

字典复杂表格顺序存储
r1 = {'name':'高1','age':18,'salary':2000,'city':'shanghai'}
r2 = {'name':'高2','age':19,'salary':3000,'city':'beijing'}
r3 = {'name':'高3','age':20,'salary':4000,'city':'guangzhou'}
tb = [r1,r2,r3]
print(tb[2].get('salary'))
for i in range(len(tb)):
? ? ? print(tb[i].get('name'),tb[i].get('age'),tb[i].get('salary'),tb[i].get('city'),)



pycharm的运用
双分支选择结构：
s = input('输入一个数：')
if int(s)<10:
    print('数小于10')
else:
    print('数大于等于10')

print('s<10' if int(s)<10 else 's>=10')

?

?

?

?

选择结构嵌套：
score = int(input('输入分：'))
grade = ''
if score<60:
    grade = '不及格'
elif score<80:
    grade = '及格'
elif score<90:
    grade = '良好'
else:
    grade = '优秀'
print('分数{0}，等级{1}'.format(score,grade))

?

score = int(input('输入0-100的分：'))
grade = ''
if score>100 or score<0:
    score = int(input('输入错误,重输：'))
else:
    if score>=90:
        grade = 'A'
    elif score>=80:
        grade = 'B'
    elif score>=70:
        grade = 'C'
    elif score>=60:
        grade = 'D'
    else:
        grade = 'E'
    print('分数{0},等级{1}'.format(score,grade))

?

score = int(input('输入0-100的分:'))
degree= 'ABCDE'
num = 0
if score>100 or score<0:
    score = int(input('输入错误,重输：'))
else:
    num = score//10
    if num<6:num=5
    print('分数{0},等级{1}'.format(score,degree[9-num]))

?

while循环结构
num = 0
sum = 0
while num<=100:
    sum = sum+num
    num +=1
print('0-100的和',sum)

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