將成員變量/方法添加到Python生成器？

Question

我可以將成員變量/方法添加到Python生成器嗎？

我想大意如下的東西，讓我可以 「窺視」 的成員變量j：

def foo(): 
    for i in range(10): 
     self.j = 10 - i 
     yield i 

gen = foo() 
for k in gen: 
    print gen.j 
    print k 

是的，我知道我可以每次都返回i和j。但我不想這樣做。我想窺視發電機內的一個本地。

Answer 1

你可以創建一個對象，並操縱__iter__接口：

class Foo(object): 
    def __init__(self): 
     self.j = None 
    def __iter__(self): 
     for i in range(10): 
      self.j = 10 - i 
      yield i 

my_generator = Foo() 

for k in my_generator: 
    print 'j is',my_generator.j 
    print 'k is',k 

打印：

j is 10 
k is 0 
j is 9 
k is 1 
j is 8 
k is 2 
j is 7 
k is 3 
j is 6 
k is 4 
j is 5 
k is 5 
j is 4 
k is 6 
j is 3 
k is 7 
j is 2 
k is 8 
j is 1 
k is 9 

Answer 2

我覺得它很醜，但它應該做你想做的。我寧願回到I和J每一次，雖然:-)

class Foo(object): 
    def foo(self): 
     for i in range(10): 
      self.j = 10 - i 
      yield i 

genKlass = Foo() 
gen = genKlass.foo() 
for k in gen: 
    print genKlass.j 
    print k