Import a module and reimport it every time it changes.

auto_import.py

from importlib import reload, import_module
from os import stat		

class auto_import(object):

	"""
	auto_import(mod, pkg = None, brute = False, verbose=False) : 
		Description:	
		  Import a module and reimport it every time it changes.
		  Useful in a REPL, when debugging some functions from a file.
		
		Usage:
		  >> foo = auto_import('foo.py')
		  >> foo.bar()
		  ... edit foo.py
		  >> foo.bar() # <-- reloaded
		Options:
		  mod 	  - file or module to import
		  pkg 	  - package argument to importlib.import_module
		  brute   - reload the module revery time a properyt is accessed
		  verbose - if set to 1 then print a message every time a module is reloaded
		  	    if set to 2 then print a message every time a property is accessed
	
	"""
		
	def __init__(self, mod, pkg = None, brute = False, verbose=False):
		
		if mod[-3:] == ".py":
			mod = mod[:-3]
			
		self._module = import_module(mod, package = pkg)
		self._cfg = { 'verbose' : verbose, 'brute' : brute }
		
		self._reload(True)
		

	def _do_reload(self):
		module = reload(self._module)
	
		is_not_special  = lambda x: not (x[:2] == x[-2:] == '__')
		bind_values     = lambda x: (x, getattr(self._module, x))
		new_dict	= dict(map(bind_values , filter(is_not_special, dir(module))))
	
		new_dict.update({ 
			'_module' : module,  
			'_cfg' : self._cfg, 
			'_reload' : self._reload, 
			'_do_reload' : self._do_reload,  
			
			})
		
		self.__dict__.clear() 
		self.__dict__.update(new_dict	)
	def _reload(self, force=False):		
		if self._cfg['brute'] or force:
			print("Reloading: brute option set to True or forced") \
				if self._cfg['verbose'] else None 
			self._do_reload()
			return 
		
		attrs  = dir(self._module)
		file   = self._module.__file__   if '__file__' in attrs else None
		cached = self._module.__cached__ if '__cached__' in attrs else None
		
		if None in [file, cached]:
			print("Reloading: __file__ or __cache__ attributes not set") \
				if self._cfg['verbose'] else None 
			self._do_reload()
			return 
		else:
			
			ftime = stat(file).st_atime
			ctime = stat(cached).st_atime
			if ftime > ctime:
				print("Reloading: cache is older then file") \
					if self._cfg['verbose'] else None 
				self._do_reload()
				return 
		
		print('Not Relaoding') if self._cfg['verbose'] == 2 else None 

		

		
	def __getattribute__(self, item):
		if item not in ['_module','_reload', '_do_reload', '__dict__', '_cfg']:		
			self._reload()
		return super().__getattribute__(item)