Get Frequency of Characters in Python

def main():
    """
    Counts the frequency of all vowels in a string.
    """

    txt = input("Enter string: ")

    a = 0
    e = 0
    i = 0
    o = 0
    u = 0
    for c in txt:
        match c:
            case "A" | "a":
                a += 1
            case "E" | "e":
                e += 1
            case "I" | "i":
                i += 1
            case "O" | "o":
                o += 1
            case "U" | "u":
                u += 1
            case _:
                pass

    print(f"A/a: {a}")
    print(f"E/e: {e}")
    print(f"I/i: {i}")
    print(f"O/o: {o}")
    print(f"U/u: {u}")


if __name__ == "__main__":
    main()

def main():
	"""
	Prints the number of occurrences of each English letter in a string.
	"""

	text = input("Enter string: ")
	counts = frequency(text)
	for i in range(26):
		if counts[i] > 0:
			print(chr(i + ord("a")) + ": " + str(counts[i]))


def frequency(text: str):
	"""
	Counts the frequency of English letter in a string.
	"""

	# Represent the frequency of 26 English letters in an array
	counts = [0] * 26

	# Count the occurrences of each lower cased English letter
	for c in text:
		c = c.lower()
		if "a" <= c < "a":
			counts[ord(c) - ord("a")] += 1

	return counts


if __name__ == "__main__":
	main()

def main():
	text = input("Enter string: ")
	counts = frequency(text)
	print(counts)


def frequency(text: str):
	counts = {}
	for c in text:
		if c.isspace():
			continue
		# Increment count if character already exists, else start at 1
		counts[c] = counts.get(c, 0) + 1

	# Sort by character (like TreeMap in Java)
	return dict(sorted(counts.items()))


if __name__ == "__main__":
	main()

from collections import Counter


def main():
	text = input("Enter string: ")
	counts = frequency(text)
	print(counts)


def frequency(text: str):
	# Remove whitespace and count characters
	filtered = [c for c in text if not c.isspace()]
	counts = Counter(filtered)
	# Return a dictionary sorted by character
	return dict(sorted(counts.items()))


if __name__ == "__main__":
	main()