Day and Night Time Lapse with RaspberryPI

#!/usr/local/bin/python3

import cv2
import argparse
import os
import functools
from functools import cmp_to_key

def help ():
	with open(__file__, "r", encoding="UTF-8") as open_file:
		for line in open_file:
			if ":" in line and "def" in line and "if " not in line:
				print(line.split(" ")[1])

#Function to check if string can be cast to int
def isnum (num):
	try:
		int(num)
		return True
	except:
		return False

#Numerically sorts filenames
def image_sort_name (x,y):
	
	x = int(x.split(".")[0])
	y = int(y.split(".")[0])
	return x-y

#Sort filenames by their last edited datetime stamp
#This way, even if you didn't name and number your frames, you can still use their order of creation for sorting
#10/10! :)
def image_sort_datetime (x,y):
	x = os.path.getmtime(x)
	y = os.path.getmtime(y)
	return x - y

def render ():
	# Construct the argument parser and parse the arguments
	arg_parser = argparse.ArgumentParser()
	arg_parser.add_argument("-e", "--extension", required=False, default='png', help="Extension name. default is 'png'.")
	arg_parser.add_argument("-o", "--output", required=False, default='output.mp4', help="Output video file.")
	arg_parser.add_argument("-d", "--directory", required=False, default='.', help="Specify image directory.")
	arg_parser.add_argument("-fps", "--framerate", required=False, default='10', help="Set the video framerate.")
	arg_parser.add_argument("-s", "--sort", required=False, default='numeric', help="Determines the type of file-order sort that will be used. Current values: none, numeric, datetime")
	arg_parser.add_argument("-t", "--time", required=False, default='none', help="Sets the framerate so that the video length matches the time in seconds.")
	arg_parser.add_argument("-v", "--visual", required=False, default='false', help="If 'true' then will display preview window.")
	arg_parser.add_argument("-safe", "--safe", required=False, default='true', help="If 'false' then will try to render all images, not just consistenly-sized ones.")
	args = vars(arg_parser.parse_args())

	# Arguments
	dir_path = args['directory']
	ext = args['extension']
	output = args['output']
	framerate = args['framerate']
	sort_type = args['sort']
	time = args['time']
	visual = args['visual']

	#Flips bools to a bool-type
	visual = visual == "true"
	safe = args['safe'] == "true"

	#Sets the framerate to argument, or defaults to 10
	if not isnum(framerate):
		framerate = 10
	else:
		framerate = int(framerate)

	#Get the files from directory
	images = []
	for f in os.listdir(dir_path):
		if f.endswith(ext):
			images.append(f)

	#Sort the files found in the directory
	if sort_type == "numeric":
		int_name = images[0].split(".")[0]
		if isnum(int_name):
			images = sorted(images, key=cmp_to_key(image_sort_name))
		else:
			print("Failed to sort numerically, switching to alphabetic sort")
			images.sort()
	elif sort_type == "datetime":
		images = [dir_path + "/" + im for im in images]
		images = sorted(images, key=cmp_to_key(image_sort_datetime))
		images = ["".join(im.split(dir_path + "/")[1:]) for im in images]
	elif sort_type == "alphabetic":
		images.sort()

	#Change framerate to fit the time in seconds if a time has been specified.
	#Overrides the -fps arg
	if isnum(time):
		framerate = int(len(images) / int(time))
		print("Adjusting framerate to " + str(framerate))

	# Determine the width and height from the first image
	image_path = os.path.join(dir_path, images[0])
	frame = cv2.imread(image_path)

	if visual:
		cv2.imshow('video',frame)
	regular_size = os.path.getsize(image_path)
	height, width, channels = frame.shape

	# Define the codec and create VideoWriter object
	fourcc = cv2.VideoWriter_fourcc(*'mp4v') # Be sure to use lower case
	out = cv2.VideoWriter(output, fourcc, framerate, (width, height))

	for n, image in enumerate(images):
		image_path = os.path.join(dir_path, image)
		image_size = os.path.getsize(image_path)
		if image_size < regular_size / 1.5 and safe:
			print("Cancelled: " + image)
			print("Abnormal image size. Use the '-safe false' to disable this check")
			continue

		frame = cv2.imread(image_path)
		out.write(frame) # Write out frame to video
		if visual:
			cv2.imshow('video', frame)

		if (cv2.waitKey(1) & 0xFF) == ord('q'): # Hit `q` to exit
			break
		if n%100 == 0:
			print("Frame " + str(n))

	# Release everything if job is finished
	out.release()
	cv2.destroyAllWindows()

	print("The output video is {}".format(output))
render()