python執行個體變量初始化_Python：自動初始化執行個體變量？

I have a python class that looks like this:

class Process:

def __init__(self, PID, PPID, cmd, FDs, reachable, user):

followed by:

self.PID=PID

self.PPID=PPID

self.cmd=cmd

...

Is there any way to autoinitialize these instance variables, like C++'s initialization list? It would spare lots of redundant code.

解決方案

Edit: extended the solution to honor default arguments also

Here is the complete solution:

from functools import wraps

import inspect

def initializer(func):

"""

Automatically assigns the parameters.

>>> class process:

... @initializer

... def __init__(self, cmd, reachable=False, user='root'):

... pass

>>> p = process('halt', True)

>>> p.cmd, p.reachable, p.user

('halt', True, 'root')

"""

names, varargs, keywords, defaults = inspect.getargspec(func)

@wraps(func)

def wrapper(self, *args, **kargs):

for name, arg in list(zip(names[1:], args)) + list(kargs.items()):

setattr(self, name, arg)

for name, default in zip(reversed(names), reversed(defaults)):

if not hasattr(self, name):

setattr(self, name, default)

func(self, *args, **kargs)

return wrapper

Edit: Adam asked me to extend the solution to support keyword arguments

from functools import wraps

import inspect

def initializer(fun):

names, varargs, keywords, defaults = inspect.getargspec(fun)

@wraps(fun)

def wrapper(self, *args, **kargs):

for name, arg in zip(names[1:], args) + kargs.items():

setattr(self, name, arg)

fun(self, *args, **kargs)

return wrapper

You can use a decorator:

from functools import wraps

import inspect

def initializer(fun):

names, varargs, keywords, defaults = inspect.getargspec(fun)

@wraps(fun)

def wrapper(self, *args):

for name, arg in zip(names[1:], args):

setattr(self, name, arg)

fun(self, *args)

return wrapper

class process:

@initializer

def __init__(self, PID, PPID, cmd, FDs, reachable, user):

pass

Output:

>>> c = process(1, 2, 3, 4, 5, 6)

>>> c.PID

1

>>> dir(c)

['FDs', 'PID', 'PPID', '__doc__', '__init__', '__module__', 'cmd', 'reachable', 'user'