在函数中同时返回布尔值和变量？ 蟒蛇

Question

Is it possible to return a boolean and a variable from a function in python

def foo(self, x):
    if x > 5:
       y = 2  #for workaround with pass by reference method 
       return true , y

# calling it by
i = 0
for i in range (0,10): 
    if foo(i):
        ref_value = y  #to get the reference value 

Answer 1

Yes, your above code returns a tuple , you can return multiple values like that (in a tuple or a list, etc) , but you will have to accept them ( unpack ) all at the calling side as well (either accept them all, or accept the tuple/list as a single element). Example/Demo -

>>> def foo(i):
...     if i > 5:
...             y = 2
...             return True, y
...     return False,0
...
>>> for i in range(0,10):
...     x,y = foo(i)
...     if x:
...             ret_value = y
...     else:
...             ret_value = 0
...     print(ret_value)
...
0
0
0
0
0
0
2
2
2
2
>>> type(foo(6))        #Example to show type of value returned.
<class 'tuple'>

Answer 2

Yes, you would need to unpack both values from the returned result:

i = 0
for i in range (0,10):
    cond, y = foo(i) 
    if cond:
        ref_value = y