小编paw*_*cki的帖子

CPython 3.6.4:

from functools import partial

def add(x, y, z, a):
    return x + y + z + a

list_of_as = list(range(10000))

def max1():
    return max(list_of_as , key=lambda a: add(10, 20, 30, a))

def max2():
    return max(list_of_as , key=partial(add, 10, 20, 30))

现在:

In [2]: %timeit max1()
4.36 ms ± 42.3 µs per loop (mean ± std. dev. of 7 runs, 100 loops each)

In [3]: %timeit max2()
3.67 ms ± 25.9 µs per loop (mean ± std. dev. of …

在Python中,您可以使用这样的with语句(源代码):

class controlled_execution:
    def __enter__(self):
        # set things up
        return thing
    def __exit__(self, type, value, traceback):
        # tear things down

with controlled_execution() as thing:
     # some code

在Flask/Jinja2中,使用flash消息的标准过程如下(源):

{% with messages = get_flashed_messages() %}
  {% if messages %}
    {% for message in messages %}
      <!-- do stuff with `message` -->
    {% endfor %}        
  {% endif %}
{% endwith %}

我想知道{% with messages = get_flashed_messages() %}语法方面的工作原理.

我无法在纯Python中重新创建它:

• with messages = get_flashed_messages(): pass 加薪 …