python文件读写操作

读写小文件

eg

with open('1.txt','r') as f:
    with open('2.txt',"w") as f1:
        b=f.readlines()
        print('--------')
        print(b)
        print('++++++++++++++++++')

        for x in b:
            f1.write(x)
            print(x)


读写大文件
方法一重载，可以做文件传输

with open('1.txt','rb') as f:
    while  True:
        block=f.read(1024)
        if not block:
            break




方法2每次读取一行

with open('1.txt','rb') as f:
    while  True:
        block=f.readline()
        if not block:
            break



方法3最强大方法

with open('1.txt','r') as f:
    while  True:
        for line in f:
            # do something to line

            break