How would you do the equivalent in Python?

mjus

In perl, below code snippet can print out the data between BEGIN ~ END from a text file.

while(<IN> {
     print if (/#BEGIN/oi .. /#END/oi);
  }

I wonder : How would you do the equivalent in Python? Thank you in advance !!!

BTW: the perl code at least runs V5.8.8

llbgurs

try this:

1. import re
   
2. 
   
3. f =open("data")
   
4. pat = re.compile(r"#BEGIN(.*?)#END", re.I)
   
5. 
   
6. for line in f:
   
7.     match_obj = re.search(pat, line)
   
8.     if match_obj is not None:
   
9.         print match_obj.group(1)
   
10. 
    

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mjus

回复 2# llbgurs

Given data file as follows:

# start data test file

#BEGIN
line 1
line 2
line 3
line 4
line 5
#END

# end of data test file

then kicked off your script, it didn't output anything matched. I'm new to python, think your pattern looks ok from the point of my perl view, I guess that you forgot to turn on multiple line mode, is it ? anyway, thank you very much for your kind and quick reply.

Kabie

1. 
   
2. import sys, itertools
   
3. sys.stdout.writelines(itertools.takewhile('#END\n'.__ne__,itertools.dropwhile('#BEGIN\n'.__ne__, sys.stdin)))

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llbgurs

1. import re
   
2. 
   
3. f =open("data")
   
4. pat = re.compile(r"#BEGIN(.*?)#END", re.I|re.S)
   
5. 
   
6. text = f.read()
   
7. 
   
8. match_obj = pat.search(text)
   
9. if match_obj is not None:
   
10.         print match_obj.group()
    
11. 
    
12. f.close()
    

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This should be work, if no require to print #BEGIN and $END

try print match_obj.group(1)

mjus

回复 5# llbgurs


    It is a perfect solution !!! Thanks a lot !!!

mjus

Kabie 发表于 2011-03-26 23:33

    It looks coolest ! although it printed out below
---------------
#BEGIN
line 1
........
line 5
---------------
    It seemed not print out #END  -- it is a bug ? could you take care of it ? thank you so much !!!

Kabie

I guess you have to print '#END' manually afterwards...