Split python strings by Fixed Length

Today, a colleague gave me a bunch of mac addresses that need to be changed to a certain format. For example, if mac = '902b345fb021 'is changed to mac = '90-2B-34-5F-B0-21', he wrote a small python script, help. In fact, the string is split according to a fixed length.

There are a bunch of mac addresses in the mac.txt file: There are two methods to implement the scheme:

 
 

  
  
Method 1:
  
  
Aw.open('mac.txt ', 'R ')
  
  
A = A. readlines ()
  
  
Foraaina:
  
  
B = list (aa. strip ())
  
  
C =''
  
  
Foriinrange (len (B )):
  
  
Ifi! = 0:
  
  
Ifi % 2 = 0:
  
  
C = c + '-' + B [I]
  
  
Else:
  
  
C = c + B [I]
  
  
Else:
  
  
C = c + B [I]
  
  
Printc
  
  
A. close ()
  
  

  
  
This method is relatively simple. It was just thought of at first.
  
  

  
  
Method 2:
  
  
Importre
  
  
Aw.open('mac.txt ', 'R ')
  
  
A = A. readlines ()
  
  
Foraaina:
  
  
B = re. findall (R'. {2} ', aa)
  
  
C = '-'. join (B)
  
  
Printc
  
  
A. close ()
  
  
This method is implemented using python regular expressions, which is convenient and highly efficient in execution.
 
 
The processing result is as follows:
50-E5-49-E3-2E-CB
90-2B-34-13-EF-A6
50-E5-49-EC-BA-1C
90-2B-34-57-B1-6F
1C-6F-65-29-6D-F9
90-2B-34-13-1A-14
50-E5-49-E3-E2-F8
50-E5-49-3A-26-96
90-2B-34-5F-B0-21
90-2B-34-13-15-74
90-2B-34-18-43-BF
00-24-1D-0E-25-8D