Renaming files will not work with >1 GB file

Question

I'm using the below code to rename few hundreds of files, it works great when the file is smaller than 1GB in size, but when it encounter larger files it doesn't extract anything and the resulted file name is blank.

import os, linecache

for filename in os.listdir(path):
    if not filename.startswith("out"): continue # less deep
    file_path = os.path.join(path, filename) # folderpath + filename
    fourteenline = linecache.getline(file_path, 14) # maybe 13 for 0-based index?
    new_file_name = fourteenline[40:40+50].rstrip() # staring at 40 with length of 50
    os.rename(file_path, os.path.join(path, new_file_name))

Answer 1

Don't use linecache. It reads the entire files in memory and fails quietly when running out of memory.

Just open each file and read 14 lines in a simple loop, or with help of itertools.islice.