Custom GDScript debug print statement that lets you know which file/line the print is being called from and also has a rate limit feature which is useful to use in _physics_process/_process(). I like to add Debug.gd as an Autoload script and name it "D". I can then just write D.print("Hello world", 1.0) in my code.

Debug.gd

extends Node

var _rate_limits: = {}

func print(val, rate_limit: = 0.0):
	# rate_limit is how often to print in seconds.
	var stack = get_stack()
	var source_file = stack[1].source
	var source_function = stack[1].function
	var source_line = stack[1].line
	var source_name =  source_file.rsplit("/", true, 1)[-1]
	var identifier = "%s|%s|%s" % [source_file, source_function, source_line]
	
	var formatted = "[%s:%s] %s" % [source_name, source_line, val]
	# Uncomment below if you want it to be formatted exactly like GDScript's built-in print_debug() statement
	# formatted = "%s\n   At: %s:%s:%s()" % [val,  source_file, source_line, source_function]
	
	var last_printed = _rate_limits.get(identifier, -INF)

	if OS.get_ticks_msec() - last_printed > rate_limit * 1000:
		print(formatted)
		if rate_limit > 0:
			_rate_limits[identifier] = OS.get_ticks_msec()

NOTE: THIS IS FOR DEBUG USE ONLY. DO NOT LEAVE THIS IN YOUR FINAL GAME! See GDQuest's tweet.