循环python中的函数调用

Question

I do have following problem -

dict1 = {'abc': {'x': 2, 'y': 3, 'z': 4}, 'mno': {'p': 3, 'q':4, 'r':5}} 

def refine():
    def calc(a_dict):
        if some_condition :
           return x ={'a':1}
        else:
           return None

    for k, v in dict1:
        return calc(v)

Now when I am iterating this function call inside a for loop , I get either None or a . The function call is such that I can get maximum of one a .

Sample Output -

None
None
{'a':1}
None

What I want calc function to return None in case all the values after the loop gives None or x in case any of the values after loop gives x .How can this be achieved ? Thanks in advance.

Edit - What if I store the results in a list and want to check if the list has something else than None and if True return it.

Answer 1

If I did get the question, you may store results of conditions applied on a dictionary and then check with all quantifier function:

def calc(a_dict):
    results = (some_condition(k,v) for k,v in a_dict.iteritems())
    if all(res == None for res in results):
        return None
    elif all(res == <something> for res in results):
        return {'a':1}
    else:
        return <something different>

Answer 2

u can use any() . any check for the condition if any one value is true. it return x . if all values fail it goes to else

if any(somecondition):
    return x
else:
    return None