Change String Case to Toggle Case in Python

def main():
	"""
	Converts a string to toggle case.
	"""

	text = input("Enter string: ")

	builder = list(text)  # Convert string to a list for mutability
	uppered = True
	for i in range(len(builder)):
		c = builder[i]
		if c.isalpha():
			c = c.upper() if uppered else c.lower()
			builder[i] = c
			uppered = not uppered
	text = "".join(builder)  # Convert list back to string

	print(text)


if __name__ == "__main__":
	main()