python3爬虫学习笔记

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原文记录内容太多现进行摘录和分类

python3的文本处理

jieba库的使用

pip3 install jieba

统计hamlet.txt文本中高频词的个数

讲解视频

kou@ubuntu:~/python$ cat ClaHamlet.py 
#!/usr/bin/env python
# coding=utf-8

#e10.1CalHamlet.py
def getText():
    txt = open("hamlet.txt", "r").read()
    txt = txt.lower()
    for ch in '!"#$%&()*+,-./:;<=>?@[\\]^_‘{|}~':
        txt = txt.replace(ch, " ")   #将文本中特殊字符替换为空格
    return txt
hamletTxt = getText()
words  = hamletTxt.split()
counts = {}
for word in words:			
    counts[word] = counts.get(word,0) + 1
items = list(counts.items())
items.sort(key=lambda x:x[1], reverse=True) 
for i in range(10):
    word, count = items[i]
    print ("{0:<10}{1:>5}".format(word, count))

统计三国演义任务高频次数

#!/usr/bin/env python
# coding=utf-8

#e10.1CalHamlet.py
def getText():
    txt = open("hamlet.txt", "r").read()
    txt = txt.lower()
    for ch in '!"#$%&()*+,-./:;<=>?@[\\]^_‘{|}~':
        txt = txt.replace(ch, " ")   #将文本中特殊字符替换为空格
    return txt
hamletTxt = getText()
words  = hamletTxt.split()
counts = {}
for word in words:			
    counts[word] = counts.get(word,0) + 1
items = list(counts.items())
items.sort(key=lambda x:x[1], reverse=True) 
for i in range(10):
    word, count = items[i]
    print ("{0:<10}{1:>5}".format(word, count))

爬虫

学习资源是中国大学mooc的爬虫课程。《嵩天老师》
下面写几个简单的代码！熟悉这几个代码的书写以后基本可以完成需求！

爬取百度首页

import requests

r = requests.get("https://www.baidu.com")
fo = open("baidu.txt", "w+")
r.encoding =  'utf-8'
str = r.text
line = fo.write( str )

爬取京东某手机页面

import requests
url = "https://item.jd.com/2967929.html"
try:
    r = requests.get(url)
    r.raise_for_status()//如果不是200就会报错
    r.encoding = r.apparent_encoding//转utf-8格式
    print(r.text[:1000])//只有前1000行
except:
    print("False")
 fo.close()

BeautifulSoup

使用request进行爬取，在使用 BeautifulSoup进行处理！拥有一个更好的排版

fo = open("jingdong.md","w")

url = "https://item.jd.com/2967929.html"
try:
    r = requests.get(url)
    r.encoding = r.apparent_encoding
    demo = r.text
    soup = BeautifulSoup(demo,"html.parser")
    fo.write(soup.prettify())
    fo.writelines(soup.prettify())
except:
    print("False")

fo.close()

BeautifulSoup爬取百度首页

fo = open("baidu.md","w")

try:
    r = requests.get("https://www.baidu.com")
    r.encoding = r.apparent_encoding
    demo = r.text
    soup = BeautifulSoup(demo,"html.parser")
    fo.write(soup.prettify())
    fo.writelines(soup.prettify())
except:
    print("False")
fo.close()

附赠
爬虫和python例子开源链接