Python File processing Exercises

1, Analog CP command Copy file (image, video) to other paths

With open (' a.txt ', ' RB ')  as f,open (' B.txt ', ' WB ')  as write:         #选择rb模式, support all copies, the corresponding write mode is WB, directly processing is the bytes type         for  line in f:                                                                     #遍历源文件的每一行               write.write (line)                                                            #写入新文件write中 

However, this does not support the user to pass parameters, so the final code is as follows:

Import Sysif len (SYS.ARGV) <3: #用户输入参数少于3个 print (' Python3 copy.py source.file Targ Et.file ') #提示用户命令的用法需要3个参数 sys.exit () with open (R '%s '%sys.argv[1], ' RB ') as F,open (R '%s '%sys.argv[2], ' WB ') as Write : #这里处理的文件是基于用户输入的参数取到的 for line in F:write.write (line)

2, Python simulation tail command, display the contents of the log file, do not exit

Python3 tail.pyimport sysimport timewith open (R '%s '  %sys.argv[2], ' RB ')  as  Read:    read.seek (0,2)                              # The 2 pattern is referenced at the end, and the previous 0 represents the last byte, guaranteeing that the cursor is directly at the tail of the file     while True:         line=read.readline ()         if line:                                      #如果行有内容              print (Line.decode (' Utf-8 '), end= ')       #默认是字节码, converted to characters, end equals null indicates line breaks do not line up individually         else:        &nbSp;    time.sleep (0.2)                       #休息0.2 seconds to make a judgment.

Python File processing Exercises