code: def isword(somestr):
  	
  	# 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
docs: 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: