<?xml version="1.0" encoding="utf-8" ?><rss version="2.0"><channel><title><![CDATA[Python_allthing的博客]]></title><description><![CDATA[]]></description><link>https://blog.youkuaiyun.com/Python_allthing</link><language>zh-cn</language><generator>https://blog.youkuaiyun.com/</generator><copyright><![CDATA[Copyright &copy; Python_allthing]]></copyright><item><title><![CDATA[python爬虫—正则表达式的使用]]></title><link>https://blog.youkuaiyun.com/Python_allthing/article/details/122901167</link><guid>https://blog.youkuaiyun.com/Python_allthing/article/details/122901167</guid><author>Python_allthing</author><pubDate>Sat, 12 Feb 2022 19:59:39 +0800</pubDate><description><![CDATA[python爬虫—正则表达式的使用
“”"
^匹配字符串的开头
$匹配字符串的结尾
.匹配任意字符除了换行符，当re.DOTALL标记被指定时，则可以匹配包括换行的任意字符
[…]用来表示一组字符，单独列出，[adas]匹配’a’‘d’;‘a’‘s’
[^…]匹配不在[]中的字符
re* 匹配0和或多和表达式
re+ 匹配一个或多个的表达式
re? 匹配0或1个由前面的正则表达式定义的片段，非贪婪方式
re{n}
re{n,} 精确匹配N个前面表达式
re{n,m} 匹配n到m次由前面的正则表达式定义的片段]]></description><category></category></item><item><title><![CDATA[python爬虫—URLError的使用]]></title><link>https://blog.youkuaiyun.com/Python_allthing/article/details/122901151</link><guid>https://blog.youkuaiyun.com/Python_allthing/article/details/122901151</guid><author>Python_allthing</author><pubDate>Sat, 12 Feb 2022 19:55:50 +0800</pubDate><description><![CDATA[python爬虫—URLError的使用,能够看到结果是404,还是超时
from urllib.request import Request,urlopen
from fake_useragent import UserAgent
from urllib.error import  URLError

url ="https://www.baidu123.comasda/"

headers = {
    "User-Agent":UserAgent().chrome

}
try:
    reque]]></description><category></category></item><item><title><![CDATA[python爬虫—requests库的用法]]></title><link>https://blog.youkuaiyun.com/Python_allthing/article/details/122877235</link><guid>https://blog.youkuaiyun.com/Python_allthing/article/details/122877235</guid><author>Python_allthing</author><pubDate>Fri, 11 Feb 2022 11:48:43 +0800</pubDate><description><![CDATA[python爬虫—requests库的用法
总结：get、post等用法…
import requests
req = requests.get("https://www.baidu.com/?tn=15007414_8_dg")
req = requests.post("https://www.baidu.com/?tn=15007414_8_dg")
req = requests.put("https://www.baidu.com/?tn=15007414_8_dg")
req = requests.]]></description><category></category></item><item><title><![CDATA[python爬虫—proxy的使用]]></title><link>https://blog.youkuaiyun.com/Python_allthing/article/details/122877113</link><guid>https://blog.youkuaiyun.com/Python_allthing/article/details/122877113</guid><author>Python_allthing</author><pubDate>Fri, 11 Feb 2022 11:35:56 +0800</pubDate><description><![CDATA[python爬虫—proxy的使用
使用代理ip,使用proxy来设置代理服务器，一段时间换一个Ip,HTTPHandler
#使用代理ip,使用proxy来设置代理服务器，一段时间换一个Ip
from urllib.request import Request
from  urllib.request import build_opener
from fake_useragent import UserAgent
from urllib.request import HTTPHandler
from ur]]></description><category></category></item><item><title><![CDATA[python爬虫——https请求]]></title><link>https://blog.youkuaiyun.com/Python_allthing/article/details/122877010</link><guid>https://blog.youkuaiyun.com/Python_allthing/article/details/122877010</guid><author>Python_allthing</author><pubDate>Fri, 11 Feb 2022 11:31:54 +0800</pubDate><description><![CDATA[python爬虫——https请求
from urllib.request import Request,urlopen
from fake_useragent import UserAgent
import ssl
url = "https://www.12306.cn/index/"
headers = {
    "User-Agent":UserAgent().random
}
request = Request(url,headers = headers)
#忽略SSL证书
# context =]]></description><category></category></item><item><title><![CDATA[python爬虫cookie的使用包括已经登录和未登录两种情况]]></title><link>https://blog.youkuaiyun.com/Python_allthing/article/details/122836888</link><guid>https://blog.youkuaiyun.com/Python_allthing/article/details/122836888</guid><author>Python_allthing</author><pubDate>Wed, 09 Feb 2022 10:39:34 +0800</pubDate><description><![CDATA[记录的身份信息 cookie
已经登陆过的cookie来进入网站
在这里插入代码片
没有登陆过的cookie来进入网站
from urllib.request import Request,urlopen
from fake_useragent import UserAgent
from urllib.parse import urlencode
from urllib.request import HTTPCookieProcessor,build_opener
#登录
login_url = “http]]></description><category></category></item><item><title><![CDATA[python爬虫get、fake_useragent、post请求、ajax请求的使用方法]]></title><link>https://blog.youkuaiyun.com/Python_allthing/article/details/122820811</link><guid>https://blog.youkuaiyun.com/Python_allthing/article/details/122820811</guid><author>Python_allthing</author><pubDate>Tue, 08 Feb 2022 11:36:35 +0800</pubDate><description><![CDATA[get请求
fake_useragent仿造用户名
post请求
ajax请求
1.看网页源代码有无信息2.看请求头和网址是否一致3.看是否有xml文件


]]></description><category></category></item><item><title><![CDATA[python爬虫报错: ＜urlopen error [SSL: CERTIFICATE_VERIFY_FAILED]]]></title><link>https://blog.youkuaiyun.com/Python_allthing/article/details/122806207</link><guid>https://blog.youkuaiyun.com/Python_allthing/article/details/122806207</guid><author>Python_allthing</author><pubDate>Mon, 07 Feb 2022 11:23:11 +0800</pubDate><description><![CDATA[python爬虫报错:&lt;urlopen error [SSL: CERTIFICATE_VERIFY_FAILED]
导入ssl 库可以解决  import ssl

]]></description><category></category></item><item><title><![CDATA[python函数中的globals()和locals()用法以及高阶函数的执行顺序]]></title><link>https://blog.youkuaiyun.com/Python_allthing/article/details/122799157</link><guid>https://blog.youkuaiyun.com/Python_allthing/article/details/122799157</guid><author>Python_allthing</author><pubDate>Sun, 06 Feb 2022 16:20:00 +0800</pubDate><description><![CDATA[python函数中的globals()和locals()用法
高阶函数的执行顺序


]]></description><category></category></item><item><title><![CDATA[local variable ‘count‘ referenced before assignment]]></title><link>https://blog.youkuaiyun.com/Python_allthing/article/details/122796134</link><guid>https://blog.youkuaiyun.com/Python_allthing/article/details/122796134</guid><author>Python_allthing</author><pubDate>Sun, 06 Feb 2022 10:35:02 +0800</pubDate><description><![CDATA[python函数常见错误
UnboundLocalError：local variable ‘count’ referenced before assignment
错误：赋值前引用的局部变量"count"
错误原因：局部作用域不能改变全局作用域的变量，当python解释器读取到局部作用域时，发现你对一个变量进行修饰的操作，解释器会认为你在局部已经定义过这个局部变量了，他就从这局部寻找这个变量，没有定义，报错了
count = 1
def func():
count+=2
print(count)
错误分析]]></description><category></category></item><item><title><![CDATA[python函数的全局、局部名称空间及作用域]]></title><link>https://blog.youkuaiyun.com/Python_allthing/article/details/122796085</link><guid>https://blog.youkuaiyun.com/Python_allthing/article/details/122796085</guid><author>Python_allthing</author><pubDate>Sun, 06 Feb 2022 10:28:26 +0800</pubDate><description><![CDATA[“”"
a = 1
def func():
return
func()
开辟一个-全局名称空间(当前py文件),将这些对应关系储存在里面,函数是储存成func:function内存地址12312312
调用函数时开辟一个-临时名称空间(函数调用或执行时才开辟),这个空间随着函数的结束而消失,调用一个函数产生一个临时空间
-内置名称空间(builting.py):python源码提供的内置函数,例如print(),input()
加载顺序:全局–内置–临时(局部)—错误  内置(内置函数最先加载)–全局(当有]]></description><category></category></item><item><title><![CDATA[python函数中万能参数*args、**kargs的应用]]></title><link>https://blog.youkuaiyun.com/Python_allthing/article/details/122791375</link><guid>https://blog.youkuaiyun.com/Python_allthing/article/details/122791375</guid><author>Python_allthing</author><pubDate>Sat, 05 Feb 2022 16:49:51 +0800</pubDate><description><![CDATA[“”"
实参角度：
1.位置参数，按照顺序一一对应 (a,b,c)对应(1,2,3)
2.关键字参数，一一对应，不用顺序 (a,b,c)对应(a=1,b=2,c=3)
3.混合参数：位置参数一定要在关键字参数之前 (a,b,c)对应(1,c=3,b=2)
形参角度：
1.与实参角度的位置参数是一种
2.默认参数：（a,b,mode = “r”）
普遍的经常使用的
3.万能参数
4.*的魔性用法
5.极限关键字参数（了解）
6.形参的最终顺序
return：可返回多个值，以元组形式返回
“”"
函数要留有修改]]></description><category></category></item><item><title><![CDATA[python函数的入门，形参以及实参的介绍]]></title><link>https://blog.youkuaiyun.com/Python_allthing/article/details/122784541</link><guid>https://blog.youkuaiyun.com/Python_allthing/article/details/122784541</guid><author>Python_allthing</author><pubDate>Fri, 04 Feb 2022 17:38:23 +0800</pubDate><description><![CDATA[python函数的入门，形参以及实参的介绍
“”"
以完成某一类事情为导向，登录，注册，一个函数就是一个功能
随调随用
减少代码的重复性，增强代码可读性
“”"

函数尽量不要出现print,当遇到函数名+(),才会被运行
return可以终止函数，给函数的执行者返回值，单个值：单个值，多个值：元组的形式返回
函数的传参，把函数盘活实参角度：
1.位置参数，按照顺序一一对应 (a,b,c)对应(1,2,3)
2.关键字参数，一一对应，不用顺序 (a,b,c)对应(a=1,b=2,c=3)
3.混合参数：位置]]></description><category></category></item><item><title><![CDATA[python字典中删除索引为奇数的面试题，倒序删除]]></title><link>https://blog.youkuaiyun.com/Python_allthing/article/details/122725182</link><guid>https://blog.youkuaiyun.com/Python_allthing/article/details/122725182</guid><author>Python_allthing</author><pubDate>Thu, 27 Jan 2022 23:37:14 +0800</pubDate><description><![CDATA[字典中删除索引为奇数的面试题
for index in range(len(l1)):
if (index) % 2 == 1:
l1.pop(index)
正着删除元素会导致后续要处理的数据索引发生变化
print(l1)
del l1[1::2]
print(l1)
l1 = [1, 2, 3, 3, 4]
l1=l1[::-1]
print(l1)
倒叙法删除元素,已经处理后的数据索引发生变化,但不影响后续数据的索引
for index in range(len(l1)-1,-1,-1):
if in]]></description><category></category></item><item><title><![CDATA[python文件操作的几种方法with open,r,w,b]]></title><link>https://blog.youkuaiyun.com/Python_allthing/article/details/122724919</link><guid>https://blog.youkuaiyun.com/Python_allthing/article/details/122724919</guid><author>Python_allthing</author><pubDate>Thu, 27 Jan 2022 23:03:51 +0800</pubDate><description><![CDATA[python文件操作的几种方法with open,r,w,b]]></description><category></category></item><item><title><![CDATA[FileNotFoundError: [Errno 2] No such file or directory: ‘F:\\python file\\无敌.text‘]]></title><link>https://blog.youkuaiyun.com/Python_allthing/article/details/122709574</link><guid>https://blog.youkuaiyun.com/Python_allthing/article/details/122709574</guid><author>Python_allthing</author><pubDate>Wed, 26 Jan 2022 22:15:41 +0800</pubDate><description><![CDATA[FileNotFoundError: [Errno 2] No such file or directory: 'F:\\python file\\无敌.text']]></description><category></category></item><item><title><![CDATA[python编码的种类以及转换以及bytes数据类型的介绍]]></title><link>https://blog.youkuaiyun.com/Python_allthing/article/details/122691375</link><guid>https://blog.youkuaiyun.com/Python_allthing/article/details/122691375</guid><author>Python_allthing</author><pubDate>Tue, 25 Jan 2022 20:09:55 +0800</pubDate><description><![CDATA[编码的种类以及转换以及bytes数据类型的介绍]]></description><category></category></item><item><title><![CDATA[python基础类型数据的补充，以及循环中列表和字典的大小问题]]></title><link>https://blog.youkuaiyun.com/Python_allthing/article/details/122683101</link><guid>https://blog.youkuaiyun.com/Python_allthing/article/details/122683101</guid><author>Python_allthing</author><pubDate>Tue, 25 Jan 2022 20:03:43 +0800</pubDate><description><![CDATA[基础类型数据的补充，以及循环中列表和字典的大小问题]]></description><category></category></item><item><title><![CDATA[python-set集合的用法以及深浅copy]]></title><link>https://blog.youkuaiyun.com/Python_allthing/article/details/122674220</link><guid>https://blog.youkuaiyun.com/Python_allthing/article/details/122674220</guid><author>Python_allthing</author><pubDate>Mon, 24 Jan 2022 20:14:00 +0800</pubDate><description><![CDATA[python-set集合的用法以及深浅copy]]></description><category></category></item><item><title><![CDATA[python的id、is的用法以及代码块的相关内容]]></title><link>https://blog.youkuaiyun.com/Python_allthing/article/details/122674182</link><guid>https://blog.youkuaiyun.com/Python_allthing/article/details/122674182</guid><author>Python_allthing</author><pubDate>Mon, 24 Jan 2022 20:10:21 +0800</pubDate><description><![CDATA[python的id、is的用法以及代码块的相关内容]]></description><category></category></item></channel></rss>