这个字典问题太坑了

list_dict = [{"year": 1916, "age": 10},
        {"year": 1826, "age": 'NaN'},
        {"year": 'NaN', "age": 7}]
for my_dict in list_dict:
    for k in my_dict:
        if isnan(float(my_dict[k])):
            my_dict[k] = 0