x模式、b模式、文件其他操作、指针移动练习

#1、通用文件copy工具实现
'''
file1=input('文件路径: ').strip()
file2=input('文件路径: ').strip()
with open(r'{}'.format(file1),mode='rb') as f1,open(r'{}'.format(file2),mode='wb') as f2:
    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
'''
with open('user.txt',mode='rt+',encoding='utf-8') as f:
    f.seek(9,0)
    f.seek(3,0)
    print(f.tell())
    cmd=f.read()
    print(cmd)
with open('user.txt',mode='w+t',encoding='utf-8') as f:
    f.seek(9,0)
    f.seek(3,0)
    print(f.tell())
    cmd=f.write('哈哈哈
')
    print(cmd) 
with open('user.txt',mode='a+t',encoding='utf-8') as f:
    f.seek(9,0)
    f.seek(3,0)
    print(f.tell())
    cmd=f.write('哈哈哈
')
    print(cmd)  

with open('user.txt',mode='rb+') as f:
    f.seek(9,1)
    f.seek(3,1)
    print(f.tell())
    cmd=f.read()
    print(cmd.decode('utf-8'))    
with open('user.txt',mode='w+b') as f:
    f.seek(9,1)
    f.seek(3,1)
    print(f.tell())
    cmd=f.write('哈哈哈
'.encode('utf-8'))
    print(cmd)
with open('user.txt',mode='a+b') as f:
    f.seek(9,1)
    f.seek(3,1)
    print(f.tell())
    cmd=f.write('哈哈哈
'.encode('utf-8'))
    print(cmd)
    
with open('user.txt',mode='rb+') as f:
    f.seek(-9,2)
    f.seek(-3,2)
    print(f.tell())
    cmd=f.read()
    print(cmd.decode('utf-8'))
with open('user.txt',mode='w+b') as f:
    cmd=f.write('哈哈哈
'.encode('utf-8'))
    cmd1=f.write('哈哈哈
'.encode('utf-8'))
    f.seek(-9,2)
    print(f.tell())
    print(f.read().decode('utf-8'))
with open('user.txt',mode='a+b') as f:
    f.seek(-9,2)
    f.seek(-3,2)
    print(f.tell())
    cmd=f.write('哈哈哈
'.encode('utf-8'))
    print(cmd)
'''
#3、tail -f access.log程序实现
'''
import time
with open('user.txt',mode='rb') as f:
    f.seek(0,2)
    while True:
        i=f.read()
        if len(i) == 0:
            time.sleep(0.5)
        else:
            print(i.decode('utf-8'),end='')
'''