Function annotations. Python 3 provides syntax to attach metadata to the parameters of a function declaration and its return value.

Annoted clip function.py

def clip(text:str, max_len:'int > 0'=80) -> str: 
 """Return text clipped at the last space before or after max_len
 """
 end = None
 if len(text) > max_len:
 space_before = text.rfind(' ', 0, max_len)
 if space_before >= 0:
 end = space_before
 else:
 space_after = text.rfind(' ', max_len)
 if space_after >= 0:
 end = space_after
 if end is None: # no spaces were found
 end = len(text)
 return text[:end].rstrip()