code: def isstring(args, quoted=False):
      
      isquoted = lambda c: c[0]==c[-1] and c[0] in ['"', "'"]
  
      if quoted:
          check = lambda c: isinstance(c, str) and isquoted(c)
      else:
          check = lambda c: isinstance(c, str)
  
      if isinstance(args, list):
          return all(map(check, args))
      else:
          return check(args)
docs: Checks if value is a (quoted) string.