python - 如何处理从 python 函数返回的空(无)元组

Question

我有一个返回元组或无的函数。来电者应该如何处理这种情况？

def nontest():
  return None

x,y = nontest()

Traceback (most recent call last):
 File "<stdin>", line 1, in <module>
TypeError: 'NoneType' object is not iterable

Answer 1

EAFP :

try:
    x,y = nontest()
except TypeError:
    # do the None-thing here or pass

或者没有try-except:

res = nontest()

if res is None:
    ....
else:
    x, y = res