Python3-文件操作

一、open（）-----read（）

stream = open(r"F:\FileOperation\lyrics.txt")
container = stream.read()
print(container)
 
print("-"*30)
 
stream = open(r"F:\FileOperation\lyrics.txt") # 默认r
containerable = stream.readable() # 判断是否可读
if containerable:
    while True:
        container = stream.readline() # 读取一行
        print(container)
        if not container:
            break
 
print("-"*30)
 
stream = open(r"F:\FileOperation\lyrics.txt")
container = stream.readlines() # 读取多行
for i in container:
    print(i)
 
 
stream = open(r"F:\FileOperation\demoDaoJi.jpg",'rb') # 图片mode应为'rb'
containerable = stream.readable()
if containerable:
    container = stream.read()
    print(container)

 

 

二、open（）----write（）

stream = open(r"F:\FileOperation\magic.txt",'w') 
# magic.txt原内容：Sweetmagic
containerable = stream.writable() # 判断是否可写
if containerable:
    container = stream.write("Hello World") 
    # write()每次都会将原来的内容清空，然后写入当前的内容
    stream.close() # 此时内容：Hello World
    # container = stream.write("Hello kitty")
    # ValueError: I/O operation on closed file.
    # 每次只要经过close（）操作，无法再写入
 
stream = open(r"F:\FileOperation\magic.txt",'w') # 原内容：Hello World
stream.writelines(["Sweet Magic\n","Sakura\n","Seele\n"]) # writelines()并没有换行效果，需要手动加"\n"
stream.close()
"""
此时内容：
Sweet Magic
Sakura
Seele
"""
 
stream = open(r"F:\FileOperation\sweet.txt",'a') 
# sweet.txt原内容：Hello World ,'a'-->append,追加，在原内容后面追加新内容
stream.write("Sweet Magic")
stream.close() # 此时内容：Hello WorldSweet Magic

 

 

三、复制

with open(r"F:\FileOperation\p1\demoDaoJi.jpg",'rb') as stream:

    container = stream.read()

    with open(r"F:\FileOperation\p2\demoDaoJi.jpg",'wb') as wstream:

        wstream.write(container)

print("文件复制完成！")