Chardet (https://github.com/chardet/chardet) automatic open (from CLI example)

open_chardet.py

from chardet.universaldetector import UniversalDetector


def open_chardet(file, *args, **kwargs):
	detector = UniversalDetector()
	with open(file, mode='rb') as fh:
		for line in fh:
			line = bytearray(line)
			detector.feed(line)
			if detector.done:
				break
	detector.close()
	if detector.result['encoding']:
		print('Detected encoding: {} (confidence {})'.format(
			detector.result['encoding'],
			detector.result['confidence']
		))
		kwargs['encoding'] = detector.result['encoding']
	return open(file, *args, **kwargs)