Question

I’m trying to write an output list to a file, but only getting the last line from the list to actually write to the file. How can I change my code so that it captures everything?

import os

slices = [(0,3), (12,28), (29,31), (32,33), (34,38), (130,144), (39,41), (32,33), (42,55), (58,64), (65,72), (73,74), (75,78), (79,84), (99,102)]
File = r"E:\file.txt"
outfile = r"E:\file_output.txt"

with open(File) as sourcefile:

for line in sourcefile: 
    result = [line[slice(*slc)] for slc in slices]

myfile = open(outfile, 'w')

for lines in result:
    myfile.write("%s\t" % lines)

myfile.close()

Answer 1

Your for loop is re-assigning result each iteration. Therefore, at the end of the loop result still only has one list in it. Assign myfile before the loop, and put the myfile.write statement inside the loop.

myfile = open(outfile, 'w')
for line in sourcefile: 
    result = [line[slice(*slc)] for slc in slices]
    myfile.write("%s\t" % result)

Alternatively, if you want to have a list of all the results, you can use += to get a list of lists, as in

result += [line[slice(*slc)] for slc in slices]