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python find position of string in entire file

Hi,

Below is a very simplified situation of my code. I'm iterating over lines in a file and on every line a regex is tried. I want the exact start position in the entire file if the regex matches. However the code below doesn't get the correct position. Any ideas? Please note, my situation doesn't allow to use a global regex on the entire file! I have to iterate over the lines.

file = open('file.txt').read()
pos = 0
match_pos = 0
for line in file.splitlines():
  match = re.search('function [^{]+?{', line)
  if match:
     match_pos = pos + match.start() #exact pos
     print match_pos
     print file.count('\n', 0, match_pos) #lineno
  
  
  pos = pos + len(line)

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HonorGod

What do you mean by "the exact start position"?

Might you be getting into trouble with your calculations because of the "newline" characters a the end of each line?

Might something like this be what you want?

import re
pat = re.compile( 'function [^{]+?{', re.MULTILINE )
fh = open( 'file.txt', 'rb' )
data = fh.read()
fh.close()
for item in re.finditer( pat, data ) :
  print '%5d..%5d' % ( item.start(), item.end() )

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Dennie

ASKER

with exact position I mean that if I would use:

m = re.finditer('searchsomething', file, flags=re.DOTALL)
m.start()

That the m.start in this code would match the start position of a match in the code of my first post (where i'm iterating over the lines)
Again, I have to iterate over all the lines!

HonorGod

Are you looking for the offset from the beginning of the file (in bytes)?
Or are you looking for the offset at the beginning of each line?

Sorry for being confused.

The snippet of code that I supplied above displays the "exact" offset of the match, both the staring and ending position.

Dennie

ASKER

"The snippet of code that I supplied above displays the "exact" offset of the match, both the staring and ending position."

Yes but I have to iterate over the lines. your example is the exact match that I'm looking for, but I can't use a global regex in the file. I can only use a regex in the line.

SOLUTION

HonorGod

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pepr

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HonorGod

Thanks for the assist, and the points.

Good luck & have a great day.