Merge the last 3 lines of each text file with specific arrangement

September 5, 2023

I have high number of txt files in E:\Desktop\Social_media\edit8\New folder directory and each file has an arrangement similar to the following:

Bolt
2,739,393
Classmates
1,267,092
SixDegrees
1,077,353
PlanetAll
552,488
theGlobe
437,847
OpenDiary
9,251
1998
MARCH
034+

Now I want to merge each txt file last 3 lines like following:

Bolt
2,739,393
Classmates
1,267,092
SixDegrees
1,077,353
PlanetAll
552,488
theGlobe
437,847
OpenDiary
9,251
034+ MARCH 1998

this mean last 3 lines must have an arrangement like number+ month year

I write following python script for this but I don’t know why not working:

import os

# Define the directory where your text files are located
directory_path = r'E:\Desktop\Social_media\edit8\New folder'

# Function to rearrange the lines and write to a new file
def rearrange_lines(file_path):
    with open(file_path, 'r') as file:
        lines = [line.strip() for line in file.readlines() if line.strip()]  # Read non-empty lines

    # Check if there are at least 3 non-empty lines
    if len(lines) >= 3:
        lines[-1], lines[-2], lines[-3] = lines[-3], lines[-2], lines[-1]  # Rearrange the last 3 lines

        # Create a new file with the rearranged lines
        with open(file_path, 'w') as file:
            file.write('\n'.join(lines))

# Iterate through each file in the directory
for root, dirs, files in os.walk(directory_path):
    for file_name in files:
        if file_name.endswith('.txt'):
            file_path = os.path.join(root, file_name)
            rearrange_lines(file_path)
            print(f'Rearranged lines in {file_name}')

print('Done!')

Where is my script problem? and how to fix it problem?

>Solution :

You’re not combining the last 3 lines into a single line in the result.

# Function to rearrange the lines and write to a new file
def rearrange_lines(file_path):
    with open(file_path, 'r') as file:
        lines = [line.strip() for line in file.readlines() if line.strip()]  # Read non-empty lines

    # Check if there are at least 3 non-empty lines
    if len(lines) >= 3:
        # reverse last 3 lines, join them with space, and replace with this result
        lines[-3:] = [' '.join(lines[-1:-4:-1])]

        # Create a new file with the rearranged lines
        with open(file_path, 'w') as file:
            file.write('\n'.join(lines))

Assigning to lines[-3:] is a slice replacement. We replace this with a list of a single line.