film + code: rewriting our imagemagick script in python

aka: how to write a command line utility in python

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Ok, you wrote it once. Are you gonna rewrite it?

YES. It currently supports individual files but I want it to support whole folders — or have the option to do so. So how do we do this? I suck at shell programming so I just decided to rewrite it all in everyone's favorite scripting/server infra language: Python.

Well, let's break down what a command line utility should do:

1. Take in arguments and parse them
2. Do some action with them

When writing command line utilities (no matter the language you are writing them in), there should be some way to take in command line arguments and parse them. A quick Google search for "command line + <YOUR LANGUAGE HERE>" should bring up the right answer.

In Python, we would use argparse as I have done here. The great thing about argparse is that it lets you add parameters in really nice and concise ways, making handling optional arguments a lot easier.

But yes, here is my script:

# author: fatcat2

import argparse
import os

from wand.color import Color
from wand.image import Image

FILE_EXTENSIONS = ["jpg", "HEIC"]

def processOutputDirectory(path, filename):
    filename = os.path.basename(filename)
    if os.path.isdir(path):
        return f"{path}/{filename}-square.jpg"
    else:
        return path

def resizeImage(filename, file_format="jpg", output_dir=None):
    image = Image(filename=filename)
    image = image.clone()

    if output_dir:
        output_dir = processOutputDirectory(output_dir, filename)

    with Color('white') as color:
        image.transform(resize="2000x2000>")
        image.gravity = 'center'
        image.extent(width=2200, height=2200, gravity="center")
        image.crop(width=2200, height=2200)
        image.background_color = color
        image.merge_layers("flatten")

    save_path = output_dir if output_dir else f"{filename}-square.{file_format}"

    image.save(filename=save_path)


if __name__ == "__main__":
    parser = argparse.ArgumentParser(description="Make your images into nice looking squares.")
    parser.add_argument("path", help="Path to the image or directory you want to convert into squares.")
    parser.add_argument("--output", "-o", help="Specify a directory to output the file to.")
    args = parser.parse_args()

    if os.path.isdir(args.path):
        for filename in os.listdir(args.path):
            if filename.split(".")[1] in FILE_EXTENSIONS:
                resizeImage(f"{args.path}/{filename}", output_dir=args.output)
    else:
        resizeImage(args.path, output_dir=args.output)