emmm......就当练习了系列08

1、通用文件copy工具实现

 src_file=input('源文件路径>>: ').strip()
 dst_file=input('源文件路径>>: ').strip()
 with open(r'{}'.format(src_file),mode='rt',encoding='utf-8') as f1,
 　　open(r'{}'.format(dst_file),mode='wt',encoding='utf-8') as f2:
 # 方法一:　　

　　res=f1.read()
 　　　　f2.write(res)

# 方法二:

　　for line in f1:
　　　　f2.write(line)

 

2、基于seek控制指针移动，测试r+、w+、a+模式下的读写内容

#r+

with open(r'h.txt', 'r+b') as f:
    print(f.read().decode('utf-8'))  # 读取源文件内容
    f.seek(0, 0)  # 指针移动到开始位置
    f.write('哈利路亚'.encode('utf-8'))  # 覆盖内容,写下'哈利路亚'
    f.seek(0, 0)
    print(f.read().decode('utf-8'))
#w+

with open(r'h.txt', 'w+b') as f:
    # w+模式打开,清空文本内容
    f.write(bytes('happy啦啦啦', encoding='utf-8'))
    f.write('yoyoyo切克闹'.encode('utf-8'))
    f.seek(5, 0)
    # 指针回到开始位置,并移动五个字节
    print(f.read().decode('utf-8'))

# a+
with open(r'h.txt', 'a+b') as f:
    f.write('
233lalala
'.encode('utf-8'))
    f.seek(-10, 2)
    f.seek(-5, 1)
    res2 = f.read().decode('utf-8')
    print(res2)

3、tail -f access.log程序实现

import time
with open('test.txt','rb') as f:
    f.seek(0,2)
    while True:
        line=f.readline()
        if line:
            print(line.decode('utf-8'))
        else:
            time.sleep(0.2)