#!/usr/bin/python
# -*- coding: UTF-8 -*-
# 例2：elif用法

num = 5
if num == 3:            # 判断num的值print 'boss'
elif num == 2:print 'user'
elif num == 1:print 'worker'
elif num < 0:           # 值小于零时输出print 'error'
else:print 'roadman'     # 条件均不成立时输出

roadman        # 输出结果

#!/usr/bin/python
# -*- coding: UTF-8 -*-# 例3：if语句多个条件

num = 9
if num >= 0 and num <= 10:    # 判断值是否在0~10之间print 'hello'
# 输出结果: hello

num = 10
if num < 0 or num > 10:    # 判断值是否在小于0或大于10print 'hello'
else:print 'undefine'
# 输出结果: undefine

num = 8
# 判断值是否在0~5或者10~15之间
if (num >= 0 and num <= 5) or (num >= 10 and num <= 15):    print 'hello'
else:print 'undefine'
# 输出结果: undefine

#!/usr/bin/python
# -*- coding:UTF-8 -*-

n= 1
while n<11:if n==7:       #if嵌套用法pass       #pass 跳过用法else:print(n)   #本行缩进n=n+1

#!/usr/bin/python
# -*- coding: utf-8 -*-

n=1
s=0
while n<101:s=s+nif n==100:print(s)else:passn=n+1
"""
求1-100的所有数的和
1+2+3+4 .....+99+100当n=1时候  s=0   。。。1当n=2时候  s=1   。。。3当n=3时候  s=3   。。。6当n=4时候  s=6   。。。10
"""

#!/usr/bin/python
# -*- coding: utf-8 -*-

n=1
while n<101:press = n%2   #取余数，余数为1说明不能整除，则为奇数if press == 0:passelse:print(n)n=n+1

#!/usr/bin/python
# -*- coding: utf-8 -*-

n=1
while n<101:press = n%2   #取余数，余数为零说明能整除，则为偶数if press ==0:print(n)else:passn=n+1

#!/usr/bin/env pyhton
# -*- coding:utf-8 -*-"""
给x赋值为0，给y赋值为0，while真，循环开始
如果x和2的余数等于0，那么x就为偶数，y的赋值就等于y减去x
否则x就为奇数，y的赋值就等于y加x
如果x等于100了，break跳出当前循环，x的赋值等于x加1一直循环到x等于100
打印y
"""
#求1-2+3-4+5...99的所有数的和
x = 0
y = 0
while True:if 0 == x % 2:y = y - xelse:y = y + xif x ==100:breakx += 1
# x=0  y=0   值0
# x=1  y=1   值1
# x=2  y=1-2   值-1
# x=3  y=-1+3 值2
# x=4  y=2-4 值-2
print(y)