Dec.30th,2019
List(列表)、Tuple(元组)、String(字符串)
print(7/3.6)
print(7//3.6)
print("______________")
b=(0)*6
print("(0)*6=",b)
print("______________")
c=[0]*6
print("[0]*6=",c)
myList = [1,2,3,4]
A = [myList]*3
print(A)
myList[2]=45
print(A)
list操作
s=(55).__add__(22)#55+22=77
print(s)
print(list(range(10)))
print('_________________________')
print(list(range(5,10)))
print('_________________________')
print(list(range(1,10,2)))
print('_________________________')
print(list(range(10,1,-1)))
print('_________________________')
print("David",'David')#单引号和双引号都可以,但不能混用
a="I'm hero forever"
print(a[7])
print(a*2)
print(len(a))
print("David",'David')#单引号和双引号都可以,但不能混用
a="I'm hero forever"
print(a.center(50))
print(a.find('e'))
print(a.split('e'))#spilt 溢出,=well,spill过去式/过去分词
a=[1,2,3,True,8]
a[0]=2**10#可行
print(a)
a[3]=2*5;
print(a)
print("__________________________")
b="21212asdadsada"
#b[0]=2*5#无效,字符串不可变
print(b)
Set(集合)
a= {3,6,"cat",4.5,False}#集合是 0 个或多个数据的无序散列容器。
print(a) #集合不允许出现重复元素,集合异质的
#空的集合表示为 set()
Dict(字典)
a=capitals = {'1':'I’m the best','2':'蔡徐坤','3':"巧碧螺"}
print(a)
print(a['1'])
for k in capitals:
print(k,"=",a[k],end="\n")
字符串格式化输出
格式操作符
name='I am CXK'
age=88
print("%s is %d years old." % (name, age))
# %字符串运算符,也叫做格式操作符
# %左边是模板或格式字符串,右边是容器(包含了格式字符串的变量值)
格式化字符串转换字符
迭代结构
wordlist = ['cat','dog','rabbit']
letterlist = [ ]
for aword in wordlist:
for aletter in aword:
letterlist.append(aletter)
print(letterlist)
============== 分界线===============
sqlist=[] //小于 10 的整数的完全平方的列表
for x in range(1,11):
sqlist.append(x*x)
print(sqlist)
a = [x * x for x in range(1, 11)]#简化
print(a)
sqlist = [x * x for x in range(1, 11) if x % 2 != 0]//1 9 25 49 81
print(sqlist)