Sorting and Merging text-files [SOLVED]

[AlphaInc]

On Windows the home path will be

C:\Users\<username>\Outputs

You can give path to where you have the .txt files,if not want to make this Outputs folder.
Eg.

outputs = Path(r'G:\div_code\answer')

Test and i write code to save lines,as redirect as show bye DeaD_EyE may not work for you as eg gzip,zcat is not a part of Windows.

from pathlib import Path

def sort_by_int(path):
    # Path has the stem attribute, which is
    # the filename without the last extension
    # to sort the paths by integer, you
    # need to get the integer part of the str
    # and convert it to an integer
    # the _ is the character where you can split
    # maxsplit=1 does only split once,
    # so you get two elements back
    # if the _ is missing, split will raise an Exception
    return int(path.stem.split("_", maxsplit=1)[1])

# Use the high level Path object
#outputs = Path.home() / "Outputs"
outputs = Path(r'G:\div_code\answer')
#print(outputs)
# Path: /home/username/Outputs

# use glob for easier search
# rglob is to search recursive
# glob and rglob replicates the shell-syntax
# the wildcard is one * and a ? stands for one character

search = "file_*.txt"
# sorted takes a key argument, which is used to define how it's sorted
# sort_by_int just returns an int and the sorted function
# is using this number to sort
sorted_outputs = sorted(outputs.glob(search), key=sort_by_int)
#print(sorted_outputs)
# the result is a list
# sorted consumes the iterable object and returns a list
# with the sorted elements

# now using this sorted list with Path objects
lines = []
for path in sorted_outputs:
    # glob does not differe between files, directories or other
    # elements
    # so you need to check, if path is a file
    if path.is_file():
        print(path)
        # if it's a file, then open it
        # the Path onject do have the method open
        # it supports like the open function a context manager
        with path.open() as fd:
            # iterating this file line by line
            # where the line end is not stripped away
            for line in fd:
                # print the line, but tell print not to add an additional
                # line end, because the line has already a line end
                print(line)
                lines.append(line.strip())
                #zf.writestr(str(path), f)
                # you can use the stdout to redirect the output
                # in your shell to a file for example or netcat
                # or gzip etc...

with open('lines.txt', 'w') as f:
    f.write('\n'.join(lines))

Output:
G:\div_code\answer\file_1.txt
line1
G:\div_code\answer\file_3.txt
line2
G:\div_code\answer\file_10.txt
line3
G:\div_code\answer\file_33.txt
line4

lines.txt:

Output:
line1
line2
line3
line4

Thanks also for your help. I can see that the Script process all my files but it does not create an output-file

Edit: My Bad, just looked after the wrong name. I found it. Thank you.

Sorry once again but I get an error:

Traceback (most recent call last):
  File "FileProcessing_11.py", line 30, in <module>
    sorted_outputs = sorted(outputs.glob(search), key=sort_by_int)
  File "FileProcessing_11.py", line 13, in sort_by_int
    return int(path.stem.split("_", maxsplit=1)[1])
IndexError: list index out of range

Could it be because the files got spaces in it?