If……else 基本结构：
|
If condition: do something else: do something |
或者
|
If condition: do something elif condition: do something else: do something |
Python 通过缩进来确定一段代码的作用域，同一级别的代码缩进要保持一致，官方建议是4个空格。
提示：IndentationError，都为代码中存在缩进错误。
小练习：
# 猜luck number,n=6
# 猜的数字比6大，提示小一点
# 猜的数字比6小，提示大一点
#猜的数字等于6，提示Bingo
代码：
#!user/bin/env python3
# -*- coding: gbk -*-
luck_num = 19
input_num = int(input("please input the luck num:"))
if input_num == 19:
print("Bingo!")
elif input_num > luck_num:
print("the num is Bigger!")
else:
print("the num is smaller")
引入循环while，加入次数限制，代码：
#!user/bin/env python3
# -*- coding: gbk -*-
luck_num = 19
input_num = int(input("please input the luck num:"))
if input_num == 19:
print("Bingo!")
elif input_num > luck_num:
print("the num is Bigger!")
else:
print("the num is smaller")
For 循环方式：
for num_of_times in range(3):
# When failure exit after three times.
input_num = int(input("please input the luck num:"))
if input_num == 19:
print("Bingo!")
break
elif input_num > luck_num:
print("the num is Bigger!")
else:
print("the num is smaller")
else:
print("you try too many times.")
continue，跳过
break，中断
for i in range(10):
if i < 5:
continue
print(i) #result
5
6
7
8
9
continue 和 break的区别
continue 是跳过当前循环块的剩余语句，进行下一次循环。break 是跳出当前循环块，停止当前循环。