是的，我也错过了 ++ 和 -- 功能。几百万行 c 代码在我的旧头脑中根深蒂固，而不是与之抗争……这是我拼凑起来的一个实现的类：
pre- and post-increment, pre- and post-decrement, addition,
subtraction, multiplication, division, results assignable
as integer, printable, settable.
这里是：
class counter(object):
def __init__(self,v=0):
self.set(v)
def preinc(self):
self.v += 1
return self.v
def predec(self):
self.v -= 1
return self.v
def postinc(self):
self.v += 1
return self.v - 1
def postdec(self):
self.v -= 1
return self.v + 1
def __add__(self,addend):
return self.v + addend
def __sub__(self,subtrahend):
return self.v - subtrahend
def __mul__(self,multiplier):
return self.v * multiplier
def __div__(self,divisor):
return self.v / divisor
def __getitem__(self):
return self.v
def __str__(self):
return str(self.v)
def set(self,v):
if type(v) != int:
v = 0
self.v = v
你可以这样使用它：
c = counter() # defaults to zero
for listItem in myList: # imaginary task
doSomething(c.postinc(),listItem) # passes c, but becomes c+1
...已经有了c，你可以这样做...
c.set(11)
while c.predec() > 0:
print c
....或者只是...
d = counter(11)
while d.predec() > 0:
print d
...对于（重新）赋值为整数...
c = counter(100)
d = c + 223 # assignment as integer
c = c + 223 # re-assignment as integer
print type(c),c # <type 'int'> 323
...虽然这将保持 c 作为类型计数器：
c = counter(100)
c.set(c + 223)
print type(c),c # <class '__main__.counter'> 323
编辑：
还有一些意想不到的（并且完全不受欢迎的）行为，
c = counter(42)
s = '%s: %d' % ('Expecting 42',c) # but getting non-numeric exception
print s
...因为在该元组内部，getitem() 不是使用的，而是对对象的引用传递给格式化函数。叹。所以：
c = counter(42)
s = '%s: %d' % ('Expecting 42',c.v) # and getting 42.
print s
...或者，更详细，更明确地说，我们真正想要发生的事情，尽管在实际形式中被冗长所反指示（改用c.v）...
c = counter(42)
s = '%s: %d' % ('Expecting 42',c.__getitem__()) # and getting 42.
print s