我想更改下面的代码

for directory, dirs, files in os.walk(directory_1):
    do_something()

for directory, dirs, files in os.walk(directory_2):
    do_something()

到此代码:

for directory, dirs, files in os.walk(directory_1) + os.walk(directory_2):
    do_something()

我得到了错误:

不支持+:'generator'和'generator'的操作数类型

如何在Python中连接两个生成器?


当前回答

在Python(3.5或更高版本)中,您可以执行以下操作:

def concat(a, b):
    yield from a
    yield from b

其他回答

使用itertools.chain.from_iterable,你可以这样做:

def genny(start):
  for x in range(start, start+3):
    yield x

y = [1, 2]
ab = [o for o in itertools.chain.from_iterable(genny(x) for x in y)]
print(ab)

我想说的是,正如用户“wjandrea”的评论所建议的那样,最好的解决方案是

def concat_generators(*gens):
    for gen in gens:
        yield from gen

它不会改变返回的类型,并且是真正的python类型。

代码示例:

from itertools import chain

def generator1():
    for item in 'abcdef':
        yield item

def generator2():
    for item in '123456':
        yield item

generator3 = chain(generator1(), generator2())
for item in generator3:
    print item

简单的例子:

from itertools import chain
x = iter([1,2,3])      #Create Generator Object (listiterator)
y = iter([3,4,5])      #another one
result = chain(x, y)   #Chained x and y

在Python(3.5或更高版本)中,您可以执行以下操作:

def concat(a, b):
    yield from a
    yield from b