Python基本语法

#coding=utf-8  

import urllib

import math

import urllib.request

from urllib.request import Request, urlopen  

from urllib.error import URLError, HTTPError

 

#定义可复用的方法

def getHtml(url):

    response = urllib.request.urlopen(url)  

    html = response.read()

    return html#方法没有return，默认返回None

#html = getHtml("http://www.baidu.com")

#print(html)

 

def getPrint(str):

    default="default"

    if(str==""):

        return default#return开始处不能与if终向对齐

    elif("special"==str):

        print("包含特殊字符");

        return "special char";

    else:

        return str#不能靠左边

ret = getPrint("special");

print(ret)

 

#异常处理机制

try:

    response = urlopen("http://www.baidu.com");

except HTTPError as e:

    print("the server couldn't fulfill the request")

except URLError as e:  

    print('We failed to reach a server.')

else:

    print("url is ok");

 

names = ["jim","lilei","haimeimei"]

for name in names:

    print(name)

 

inputChar = input()#从键盘读取输入的内容

print(inputChar)

 

#方法返回多个值

def retMultiValue(x,y,step,angle=0):

    nx = x + step*math.cos(angle)

    ny = y + step*math.sin(angle)

    return nx,ny

x,y = retMultiValue(100,100,60,math.pi / 6)

print(x,y)

#需要先将数字转换为字符串

print("x result is【"+str(x)+"】,y result is【"+str(y)+"】")

 

#返回的多个值可以是不同类型

def retDeffVal():

    return 2,"test"

f,s = retDeffVal()

print(s)