find string line startswith recursively python

Question

i have to find recursively all lines( which start with string "excel") in all files (in directory and subdirectory) .i need for each filename the line found (for example : filename1: line1 founded... filename2:

line2 founded... Output result in file called "logfile" if no line founded , filename not saved in logfile.

import os
word="excel"
from os.path import join
for (dirname, dirs, files) in os.walk('/batch/'):
    for filename in files:
      thefile = os.path.join(dirname,filename)
         for line in files: 
           if line.startswith(word):
                    print (line)
                    print (thefile)

Thanks

Answer 1

Your code just has minor problems: The biggest one is that you loop on filename instead of file content.

import os
word="excel"
from os.path import join
for (dirname, dirs, files) in os.walk('/batch/'):
    for filename in files:
        thefile = os.path.join(dirname, filename)
        with open(thefile) as f:
            for line in f:
                if line.startswith(word):
                    print (line)
                    print (thefile)

EDIT:

import os
word="excel"
from os.path import join
with open('log_result.txt', 'w') as log_file:
    for (dirname, dirs, files) in os.walk('/tmp/toto'):
        for filename in files:
            thefile = os.path.join(dirname, filename)
            with open(thefile) as f:
                lines = [line for line in f if line.startswith(word)]
            if lines:
                log_file.write("File {}:\n".format(thefile))
                log_file.writelines(lines)