专栏：002 ：python 文件操作

"读文件内容"

filename = "test.txt"
f = opne(filename,"r")
print(f.read())
f.close()

"写文件内容"
filename_2 = "write.txt"
f = opne(filename_2,"w")
f.write("I love python")
f.close()

# test.txt

---
i write this file just for fun .
how old are you .
and?
can i help you .
---


# 读文件操作

import codecs
filename = "test.txt"
with codecs.open(filename,"r",encoding="utf8") as f:
    all_content = f.readline(20)
    print(all_content)
    
---
i write this file ju     # 数下刚好20
---

# 二进制文件写入
# 将文件夹下首页的24张图片下载至本地
import requests
from lxml import etree
import codecs
url = "https://alpha.wallhaven.cc/random"
con = requests.get(url)
html = con.content

Html = etree.HTML(html)
pattern_figure = Html.xpath('//figure//@data-src')
i= 0
print(pattern_figure)
for one in pattern_figure:
    print(one)
    with codecs.open("%s.jpg" %i , "wb") as f:
        one_pic = requests.get(one)
        f.write(one_pic.content)
        i+=1