Checks that some string is a word
		
		:param str somestr:
		    It is some string that will be checked for word.
			
		    The word is a string that contains only alphabetic characters, 
		    its length not less 2 characters and 
		    noone characters does not reeats more than 2 times in a row.
			
		    The word can not be multiline
			
		:except TypeError:
		    If the checked word is not a string
			
		:return bool:

def isword(somestr):
	"""
		Checks that some string is a word
		
		:param str somestr:
		    It is some string that will be checked for word.
			
		    The word is a string that contains only alphabetic characters, 
		    its length not less 2 characters and 
		    noone characters does not reeats more than 2 times in a row.
			
		    The word can not be multiline
			
		:except TypeError:
		    If the checked word is not a string
			
		:return bool:
	"""
	# check invalid data types
	OnlyStringsCanBeChecked(somestr)
	
	if somestr.isalpha() and len(somestr) > 1:
		# find characters that repeats more then 2 times in a row
		matches = re.search(r'(.)(\1)(\1)', somestr, flags = re.IGNORECASE)
		if matches == None:
			# russian
			# check first character
			if somestr.casefold()[0:1] not in ['ъ', 'ь']:
				return True
	# in other cases
	return False