On 9/21/17 12:29 PM, Tobiah wrote:
Are these completely equivalent?
def foo(thing):
assert(thing > 0), "Thing must be greater than zero"
def foo(thing):
if not (thing > 0): raise AssertionError("Thing must be greater than
zero")
Other than the fact that the assertion can be turned off
with -O?
Let's see:
Python 3.6.2 (default, Jul 17 2017, 07:05:09)
[GCC 4.2.1 Compatible Apple LLVM 8.1.0 (clang-802.0.42)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> def foo1(thing):
... assert(thing > 0), "Thing must be greater than zero"
...
>>> def foo2(thing):
... if not (thing > 0): raise AssertionError("Thing must be
greater than zero")
...
>>> import dis
>>> dis.dis(foo1)
2 0 LOAD_FAST 0 (thing)
2 LOAD_CONST 1 (0)
4 COMPARE_OP 4 (>)
6 POP_JUMP_IF_TRUE 16
8 LOAD_GLOBAL 0 (AssertionError)
10 LOAD_CONST 2 ('Thing must be greater
than zero')
12 CALL_FUNCTION 1
14 RAISE_VARARGS 1
>> 16 LOAD_CONST 0 (None)
18 RETURN_VALUE
>>> dis.dis(foo2)
2 0 LOAD_FAST 0 (thing)
2 LOAD_CONST 1 (0)
4 COMPARE_OP 4 (>)
6 POP_JUMP_IF_TRUE 16
8 LOAD_GLOBAL 0 (AssertionError)
10 LOAD_CONST 2 ('Thing must be greater
than zero')
12 CALL_FUNCTION 1
14 RAISE_VARARGS 1
>> 16 LOAD_CONST 0 (None)
18 RETURN_VALUE
>>>
Yes, they are completely equivalent, compiling to precisely the same
bytecode.
--Ned.
--
https://mail.python.org/mailman/listinfo/python-list
