Complete the code which should return `true` if the given object is a single ASCII letter (lower or upper case), `false` otherwise.

Difficulty: EASY
Starter code: def is_letter(s):
	

Solutions:
def is_letter(s):
	return len(s) == 1 and s.isalpha()


import re

def is_letter(stg):
	return bool(re.match('[a-z]\\Z', stg, re.I))


import re

def is_letter(s):
	return bool(re.fullmatch('[A-Za-z]', s))


is_letter = lambda s: (s == s[-1:]) & s.isalpha()


import re

def is_letter(s):
	return re.match('(?i)[a-z]\\Z', s) is not None


import re

def is_letter(s):
	return bool(re.match('^[a-z]$', re.escape(s), re.I))


def is_letter(char):
	return char.isalpha() and len(char) == 1


import re

def is_letter(s):
	return bool(re.fullmatch('[a-zA-Z]', s))