集合 - lovemoganna/DataStructure GitHub Wiki

sum = 0 
for x in range(101):
    sum =sum + x 
print(sum)    

sum = 0 
n = 99 
while n >0 : 
    sum = sum + n 
    print(sum)
    n = n -2 
print(sum)    

d = {"Micheal":95,"Bob":75,"Tracy":85}
d["Adam"] = 67
d.pop("Bob")
print("Thomas" in d)
print(d.get("Thomas"))
print(d["Micheal"])
print(d)

# 进行开平方运算
import math
math.sqrt(18)

s=10
print(10//3)

thesum = thesum + 1
thesum
thesum = True
thesum

mylist= [1,3,True,6.5]
mylist[1:3]

mylist=[1,2,3,4]
A= [mylist]*3
print(A)

mylist[2] = 45 
print(A)

mylist = [1024,3,True,6.5] 
mylist.append(True)# 插入在list的末尾
mylist.insert(2,4.5)# 根据索引位置来插入
mylist.sort() # 布尔类型在前.数字按从小到大的顺序排列.
print(mylist.index(6.5))# 返回6.5所在的索引
del mylist[0] # 删除首个索引的值
print(mylist)

(54).__add__(21)

print(range(10))
print(list(range(10)))
print(list(range(5,10))) 
print(list(range(5,10,2)))# 每两个数之间相差 2（不包含 10）
print(list(range(10,1,-1)))# 倒着数数,不包含1

myName = "David"
myName[3] # 打印出第三个字符
myName * 2 # 双拼
len(myName) # 打印字符串的长度
myName.upper() # 大写表示
myName.center(1) # 返回一个字符串，w 长度，原字符串居中
myName.split('v') # 以 v 为分隔符，将原字符串分割，返回一个列表

mylist[0] = 2 ** 10
mylist
myName
myName[0]='x'# TypeError: 'str' object does not support item assignment

mytuple=(1,True,4.96)

mytuple[1] = "A"

mytuple=(2,True,4.96)
mytuple
len(mytuple)

myset = {3.6,"cat",4.5,"False"}
myset

A = {1,2,3,4}
B = {3,4,5,6}

A.union(B) # 并集
A.intersection(B) # 交集
A.difference(B) # 抛去A,B共有的,取A剩下的部分.
A.issubset(B) # 判断集合 A 中的所有元素是否都在集合 B 中. 
A.add(7)#把 item 这个元素添加到集合 A 中
A.remove(3)
A
B

myset = {False,4.5,3,6,"cat"}
yourset= {99,3,100}
myset.union(yourset)
myset|yourset # 并集
myset.intersection(yourset) # 交集
myset.difference(yourset) # 抛去myset,yourset共有的,取myset剩下的部分.
myset-yourset # {4.5, 6, False, 'cat'} 同上

{3,100}<=yourset # 包含的关系
myset.add("house")
myset
yourset
{3.100}.issubset(yourset) # False,这些元素全在yourset中,但是缺少一个.
yourset.pop()
yourset

phoneext={'david':1410,'brad':1137}
phoneext.keys()
# dict_keys(['david', 'brad'])

list(phoneext.keys())
# ['david', 'brad']

list(phoneext.values())
# [1410, 1137]

phoneext.items() # 键值对组合
# dict_items([('david', 1410), ('brad', 1137)])

list(phoneext.items())
# [('david', 1410), ('brad', 1137)]

phoneext.get("kent",111)# kent不存在,返回111

sradius=input("please enter the radius of the cirle: ")
radius = float(sradius)
diameter = 2 * radius
diameter # 输入1,显示2.0

print("Hello","World",sep="****") # Hello****World,sep代表着在中间拼接
print("Hello","Word",end="***")# Hello Word***,end代表着在尾部拼接
print(aName, "is", age, "years old.")