Function to get resolution (eg 1080p) from string (python3)

resolutionP.py

def resolutionP(string): # returns 720p from test.720p-foo and so on
	string = string.lower()
	if "0p" in string:
		index = string.index("0p")
		result = ""
		# go backwards
		while string[index].isnumeric():
			result = result + string[index]
			index -= 1
		result = result[::-1] + "p" # reverse and add p
		return result
	else:
		return "(unknown resolution)"