1.《python核心编程》的这段程序怎么理解?对于这个函数,书上说两个wraaped是闭包,但是不知道谁是自由变量。
2.代码:
from time import time
def logged(when):
def log(f, *args, **kwargs):
print '''Called:
function: %s
args: %r
kwargs %r''' % (f, args, kwargs)
def pre_logged(f):
def wraper(*args, **kwargs):
log(f, *args, **kwargs)
return f(*args, **kwargs)
return wraper
def post_logged(f):
def wrapped(*args, **kwargs):
now = time()
try:
return f(*args, **kwargs)
finally:
log(f, *args, **kwargs)
print "time delta: %s" % (time()-now)
return wrapped
try:
return {"pre": pre_logged, "post": post_logged}[when]
except KeyError, e:
raise ValueError(e), 'must bre "pre" or "post"'
@logged("post")
def hello(name):
print "Hello, ", name
hello('World!')
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