merger.py

### Merge the folder containing detection results of individual frames into a single file

import os
import argparse

# Arguments
parser = argparse.ArgumentParser('Merge the folder containing detection results of individual frames into a single file')
parser.add_argument('--folder_path',
                    type=str,
                    help="Path to the folder containing the detection files for each frame. ")
parser.add_argument('--save_path',
                    type=str,
                    help="Path to save the merged file")
args = parser.parse_args()


# Set the path to the folder containing the detection files
folder_path = args.folder_path

# Create an empty list to store the contents of each file
file_contents = []

# Loop through each file in the folder
filenames = os.listdir(folder_path)
filenames.sort()
for filename in filenames:
    if filename.endswith(".txt"):
        # Extract the frame index from the file name
        # Assiming the xxxxxx.txt format for each detection file here. If you use a different format, change this line accordingly.
        frame_index = int(filename[:6])
        
        # Open the file and read its contents
        with open(os.path.join(folder_path, filename), "r") as f:
            contents = f.read().strip().split("\n") # f.read() ends with a newline character, so we remove it with strip()
        
        if len(contents[0]) == 0:
            continue
        # Add the frame index as the first column of the contents
        modified_contents = [f"{frame_index} {line}" for line in contents]
        
        # Append the modified contents to the list
        file_contents.extend(modified_contents)

# Concatenate the contents of the list into a single string
merged_contents = "\n".join(file_contents)

# Write the concatenated string to a new file
save_path = args.save_path
if not os.path.exists(os.path.dirname(save_path)):
    os.makedirs(os.path.dirname(save_path))
with open(save_path, "w") as f:
    f.write(merged_contents)