Python练习7--if

if 用法可以查看http://www.runoob.com/python/python-if-statement.html

练习1，注意if后的冒号

#Hello World program in Python# -*- coding:utf8 -*-import os,sys#字典dict={}dict["name"]="初学"dict["say"]="晚上好"dict["detail"]="每天一练"#函数def output(k,v=" lists"):    print k,v#iffor k,v in dict.items():    if k == "say":        output(k,v)    if v=="初学":        output(k,v)

练习1运行结果

练习2：if elif else

#!python# _*_ coding: utf8 _*_import os,sysdict={}dict["name"]="初学"dict["say"]="早上好"dict["detail"] = "每天一练"#函数def output(k,v=" lists"):    print k,v#if elif else passfor k,v in dict.items():    if k == "say":        output(k,v)    elif v == "初学":        output(k,v)    else:        pass

练习2运行结果

练习3：if elif break

#!python# _*_ coding: utf8 _*_import os,sysdict={}dict["name"]="初学"dict["say"]="早上好"dict["detail"] = "每天一练"#函数def output(k,v=" lists"):    print k,v#if elif else breakfor k,v in dict.items():    if k == "say":        break    elif v == "初学":        output(k,v)    else:        output(k,v)

练习3运行结果

练习4：if elif else continue

#!python# -*- coding: utf8 -*-import os,sysdict={}dict["name"]="初学"dict["say"]="晚上好"dict["detail"]="每天一练"#函数def  output(k,v=" lists"):    print k,v#if elif else continuefor k,v in dict.items():    if k == "say":        continue    elif v == "初学":        output(k,v)    else:        output(k,v)

练习4 运行结果