流程控制

流程控制

一、分支结构

1、if else

x = int(input("please input x:"))
y = int(input("please input y:"))
if(not x>=90 and not y>=90):
    print("A")
else 
    print("B")

2、elifd 用法

if(a >=90):
    print("a>=90")
elif (a >=80):
    print("90>=a>=80")
else
    print("a<80")

三、for 循环
for 循环遍历序列，如一个列表或一个字符

语法：
for 参数 in 来源

for x in "abcd":
    print("hello world")

for x in "abcd":
    print(x,"hello world")


for x in [0,1,2,3,4,5,6]:
    print(x,"hello world")

rang[i，j[，步进值]]

for i in range(2,15,3):
    print (i)

结果

C:\Users\Administrator\AppData\Local\Programs\Python\Python35-32\python.exe C:/Users/Administrator/PycharmProjects/test/test.py
2
5
8
11
14

Process finished with exit code 0 

s = ["hello", "haha", "gogo"]
for x in range(len(s)):
    print(x, s[x])

C:\Users\Administrator\AppData\Local\Programs\Python\Python35-32\python.exe C:/Users/Administrator/PycharmProjects/test/test.py
0 hello
1 haha
2 gogo

Process finished with exit code 0