python中函数返回

pass vs return.py

Python 2.7.9 Stackless 3.1b3 060516 (default, Feb 21 2015, 11:54:09) [MSC v.1500 32 bit (Intel)]
Type "copyright", "credits" or "license" for more information.

IPython 5.1.0 -- An enhanced Interactive Python.
?         -> Introduction and overview of IPython's features.
%quickref -> Quick reference.
help      -> Python's own help system.
object?   -> Details about 'object', use 'object??' for extra details.

In [1]: def foo(): return

In [2]: import dis

In [3]: dis.dis(foo)
  1           0 LOAD_CONST               0 (None)
              3 RETURN_VALUE

In [4]: def foo(): pass

In [5]: dis.dis(foo)
  1           0 LOAD_CONST               0 (None)
              3 RETURN_VALUE

In [6]: def foo(): 1

In [7]: dis.dis(foo)
  1           0 LOAD_CONST               0 (None)
              3 RETURN_VALUE