Modify the `kebabize` function so that it converts a camel case string into a kebab case.

Notes:
  - the returned string should only contain lowercase letters

Difficulty: EASY
Starter code: def kebabize(string):
	

Solutions:
def kebabize(s):
	return ''.join((c if c.islower() else '-' + c.lower() for c in s if c.isalpha())).strip('-')


def kebabize(string):
	result = ''
	for c in string:
		if c.isupper():
			if result is not '':
				result += '-{}'.format(c.lower())
			else:
				result += c.lower()
		if c.islower():
			result += c
	return result


import re

def kebabize(s):
	s = ''.join([i for i in s if not i.isdigit()])
	kebablist = [_f for _f in re.split('([A-Z][^A-Z]*)', s) if _f]
	return '-'.join((x.lower() for x in kebablist))


import re

def kebabize(s):
	return re.sub('\\B([A-Z])', '-\\1', re.sub('\\d', '', s)).lower()


def kebabize(string):
	string_letter_list = []
	for letter in string:
		if string.isdigit():
			return ''
		elif letter == letter.upper() and string.isdigit() == False and (letter.isdigit() == False):
			string_letter_list.append('-')
			string_letter_list.append(letter.lower())
		elif letter.isdigit() == False:
			string_letter_list.append(letter)
	result = ''.join(string_letter_list)
	if result[0] == '-':
		return result[1:]
	else:
		return result


def kebabize(s):
	l = [i for i in s if i.isalpha()]
	if s.isdigit():
		return ''
	if s.isupper():
		return '-'.join(l).lower()
	for i in range(len(l) - 1):
		if (l[i].islower() or l[i].isupper()) and l[i + 1].isupper():
			l[i] += '-'
	return ''.join(l).lower()


import re

def kebabize(string):
	return re.sub('(?!^)([A-Z])', '-\\1', re.sub('\\d', '', string)).lower()


def kebabize(string):
	return ''.join((c if c.islower() else f'-{c.lower()}' for c in [c for c in string if c.isalpha()])).strip('-')


def kebabize(string):
	a = ''
	for i in string:
		if i.isupper():
			a += '-' + i.lower()
		if i.islower():
			a += i
	return a.strip('-')


def kebabize(string):
	return ''.join(list(map(transponse_char, string))).lstrip('-')

def transponse_char(char):
	if char.isdigit():
		return ''
	if char.isupper():
		return '-{}'.format(char.lower())
	return char