Quick python script for converting a buncha random image formats to one. No extensive debugging but should work

convert.py

import os
import shutil
import tempfile
import logging
from PIL import Image
import concurrent.futures
from math import ceil
import sys

SUPPORTED_EXT = [
    "JPG",
    "JPEG",
    "PNG",
    "GIF",
    "BMP",
    "PPM"
]

def verifyArgs(args: list[str]):
    # First part of argv is the executed script so I work with args[1:]
    # because I dont care about the scripts name 
    # 
    # I dont know why I would but I could change this in the future
    if args[1:] == []:
        print("Arguments cannot be empty")
        return False
    
    for arg in args[1:]:
        if arg.upper() not in SUPPORTED_EXT:
            print(f"Format {arg} not supported")
            return False
    return True

if __name__ == "__main__" and verifyArgs(sys.argv):


    NUM_OF_THREADS = 8

    format = "%(asctime)s: %(message)s"
    logging.basicConfig(format=format, level=logging.INFO, datefmt="%H:%M:%S", filename='log.log')
    directory = os.getcwd()
    files = []

    logging.debug(f"Started with args: {sys.argv}")

    for file in os.listdir(directory):
        
        filename = os.fsdecode(file)
        
        # Horrible syntax makes this hard to read but essentially
        # I take the final string after a dot in a filnameand check 
        # if its part of the supplied arguments
        if file.split(".")[-1].upper() in sys.argv[2:]: 
            files.append(filename)

    groupSize = ceil(len(files) / NUM_OF_THREADS)
    threads = []
    
    def threadFunc(name: str, files: list[str]):
        try:
            with tempfile.TemporaryDirectory() as tmpdirname:
                for filename in files:
                    # Open image handle
                    img = Image.open(filename)
                    logging.info(f"Workign on file {filename}: {name}")
                    
                    # Prepare paths to move image around
                    ext = filename.split(".")[-1]
                    if sys.argv[1].upper() == "JPG":
                        newExt = "JPEG"
                        img = img.convert("RGB")
                    else:
                        newExt = sys.argv[1]
                    newFileName = filename.replace(ext, newExt.lower())
                    tmpFilePath = os.path.join(tmpdirname, newFileName)
                    newFilePath = os.path.join(directory, newFileName)
                    
                    logging.debug(f"New file name: {newFileName}")
                    logging.debug(f"Tmp file path: {tmpFilePath}")
                    logging.debug(f"New file path: {newFilePath}")
                    
                    # Save the image
                    img.save(tmpFilePath, newExt)
                    os.remove(filename)
                    shutil.move(tmpFilePath, newFilePath)
                    logging.info(f"Finished with file {filename}: {name}")
            logging.info(f"Finished thread {name}")
        except Exception:
            logging.info("oops something happened, take a look...")
            logging.exception(Exception)
        
    # The multithreading aspect
    with concurrent.futures.ThreadPoolExecutor(max_workers=NUM_OF_THREADS) as executor:
        for threadNum in range(NUM_OF_THREADS):
            # Last group might not be full
            if threadNum == NUM_OF_THREADS - 1:
                logging.info(f"Thread responsible for files {files[threadNum*groupSize:]} to the end")
                executor.submit(threadFunc, str(threadNum + 1), files[threadNum*groupSize:])
            else:
                logging.info(f"Thread responsible for files {files[threadNum*groupSize:(threadNum+1)*groupSize]}")
                executor.submit(threadFunc, str(threadNum + 1), files[threadNum*groupSize:(threadNum+1)*groupSize])
            
            logging.info(f"Added thread {threadNum + 1}")
else:
    print("""
    Usage : script.py formatToConvertTo formatToConvertFrom ...

    To use this script you must pass the format you want to convert 
    as the first argument without the dot before it(PNG, JPG). Then list
    the formats you are trying to convert from.
    """)