Python基礎學習四 文件操做（二）

 

####讀取文件####

with open('goods_info.txt', 'r', encoding='utf-8') as f:

f.seek(0) # 注意指針位置

goods_info = eval(f.read()) # eval()將字符串str當成有效的表達式來求值並返回計算結果

 

####內容替換####

with open('123.txt','a+',encoding='utf-8') as f:

f.seek(0)

all = f.read()

new_all = all.replace('二','一')

f.seek(0)

f.truncate()

f.write(new_all)

f.flush()

 

####多文件讀取####

import os

with open('123.txt',encoding='utf-8') as f,open('333.txt','w',encoding='utf-8') as f2:

for line in f:

new_line = line.replace('一','二')

f2.write(new_line)

 

os.remove('123.txt')#刪文件

os.rename('123.txt','333')#更名

 

###圖片讀寫#####

在博客上，上傳一張圖片，保存圖片的URL

import requests

url = 'https://images2017.cnblogs.com/blog/1297828/201801/1297828-20180111115848004-1702177202.jpg'

img = requests.get(url).content

 

f = open('123.jpg','wb')# bytes ，以二進制模式打開

f.write(img)