whlie循环
一般式
x = "jianghuhehai"
while x:
print(x,end="")
x = x[1:]
结果是:
jianghuhehaiianghuhehaianghuhehainghuhehaighuhehaihuhehaiuhehaihehaiehaihaiaii
0,空值,none 是逻辑否
continue
x = 10
while x:
x -=1
if x %2 !=0:
continue
print(x,end="")
结果是:
86420
break
while True:
name = input("请输入您的姓名")
if name == "stop":
break
age = input("请输入您的年龄")
print("您好,{},您的年龄是{},欢迎您的到来".format(name,age))
print("循环结束")
结果是:
请输入您的姓名sara
请输入您的年龄32
您好,sara,您的年龄是32,欢迎您的到来
请输入您的姓名stop
循环结束
for x in range(1,5):
if x == 6:
print("有这个数字",x)
break
else:
print("未找到这个数字")
结果是:
未找到这个数字
for 循环
for x in 目标序列
# emp = {
# "name":"tom",
# "age":"30",
# "job":"fin",
# }
# for key in emp:
# print("{}=>{}".format(key,emp[key]))
emp = {
"name":"tom",
"age":"30",
"job":"fin",
}
for key in emp:
print("{}=>{}".format(key,emp.get(key,"未找到")))
两个的结果均是:
name=>tom
age=>30
job=>fin
s1 = "youpingketang"
s2 = "dajiangdahe"
# result=[]
# for x in s1:
# if x in s2:
# result.append(x)
# print(result)
l = [x for x in s1 if x in s2]
print(l)
结果均是:
[‘i’, ‘n’, ‘g’, ‘e’, ‘a’, ‘n’, ‘g’]
range(开始值,终止符号,步长) 返回生成器对象
终止符号,返回的对象不包含终止的值。
enumerate()
s = "youpinketang"
for idx, item in enumerate(s):
print("{}){}".format(idx+1,item))
结果是:
1)y
2)o
3)u
4)p
5)i
6)n
7)k
8)e
9)t
10)a
11)n
12)g