单独返回在python中做什么? [英] What does return alone do in python?

问题描述

def process_blog(blogid):博客 = get_blog(blogid)如果博客 == 无:返回别的:返回博客

第 4 行的 return 有什么作用?.当 blog == None 时它​​返回什么?

解决方案

一个空的 return(或者在函数末尾根本没有 return)等于返回无:

<预><代码>>>>导入文件>>>定义一个():...返回无...>>>定义 b():... 返回...>>>dis.dis(a)2 0 LOAD_CONST 0(无)3 RETURN_VALUE>>>dis.dis(b)2 0 LOAD_CONST 0(无)3 RETURN_VALUE

<小时>

仅供参考，您应该使用 is None 来检查 None´ 而不是 == None`.但是，在您的情况下，整个函数可以简化为这个(这使它有点毫无意义):

def process_blog(blogid):返回 get_blog(blogid)

def process_blog(blogid):
    blog = get_blog(blogid)
    if blog == None:
        return
    else:
        return blog

What does this return in the 4th line do?. What does it returns when blog == None.?

解决方案

A bare return (or no return at all at the end of the function) is equal to return None:

>>> import dis
>>> def a():
...     return None
...
>>> def b():
...     return
...
>>> dis.dis(a)
  2           0 LOAD_CONST               0 (None)
              3 RETURN_VALUE
>>> dis.dis(b)
  2           0 LOAD_CONST               0 (None)
              3 RETURN_VALUE

---

FYI, you should use is None to check against None´ instead of== None`. However, in your case the whole function can be simplified to this (which makes it somewhat pointless):

def process_blog(blogid):
    return get_blog(blogid)

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