在python中打印元组和列表的差异

Question

当我在列表和元组之间更改输出类型时，一个显示输出，而另一个只显示结果的位置。为什么会这样？

>>> symbol = '123456789'
>>> (s for s in symbol)
<generator object <genexpr> at 0x7fc0e9e2fbf8>
>>> [s for s in symbol]
['1', '2', '3', '4', '5', '6', '7', '8', '9']

Answer 1

(s for s in symbol)是生成器理解。似：

symbol = '123456789'
def func():
for s in symbol:
yield s
g = func()
print(g)
<generator object func at 0x7ffff7e59410>
print(tuple(g)) 
('1', '2', '3', '4', '5', '6', '7', '8', '9')

如果将发电机提供给list()或tuple()，发电机将运行。