Revisions to How do I avoid the "self.x = x; self.y = y; self.z = z" pattern in __init__?

added 109 characters in body

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edited Jun 9, 2019 at 7:24

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Edit: If you have python 3.7+ just use dataclasses

A decorator solution that keeps the signature:

import decorator
import inspect
import sys


@decorator.decorator
def simple_init(func, self, *args, **kws):
    """
    @simple_init
    def __init__(self,a,b,...,z)
        dosomething()

    behaves like

    def __init__(self,a,b,...,z)
        self.a = a
        self.b = b
        ...
        self.z = z
        dosomething()
    """

    #init_argumentnames_without_self = ['a','b',...,'z']
    if sys.version_info.major == 2:
        init_argumentnames_without_self = inspect.getargspec(func).args[1:]
    else:
        init_argumentnames_without_self = tuple(inspect.signature(func).parameters.keys())[1:]

    positional_values = args
    keyword_values_in_correct_order = tuple(kws[key] for key in init_argumentnames_without_self if key in kws)
    attribute_values = positional_values + keyword_values_in_correct_order

    for attribute_name,attribute_value in zip(init_argumentnames_without_self,attribute_values):
        setattr(self,attribute_name,attribute_value)

    # call the original __init__
    func(self, *args, **kws)


class Test():
    @simple_init
    def __init__(self,a,b,c,d=4):
        print(self.a,self.b,self.c,self.d)

#prints 1 3 2 4
t = Test(1,c=2,b=3)
#keeps signature
#prints ['self', 'a', 'b', 'c', 'd']
if sys.version_info.major == 2:
    print(inspect.getargspec(Test.__init__).args)
else:
    print(inspect.signature(Test.__init__))

A decorator solution that keeps the signature:

import decorator
import inspect
import sys


@decorator.decorator
def simple_init(func, self, *args, **kws):
    """
    @simple_init
    def __init__(self,a,b,...,z)
        dosomething()

    behaves like

    def __init__(self,a,b,...,z)
        self.a = a
        self.b = b
        ...
        self.z = z
        dosomething()
    """

    #init_argumentnames_without_self = ['a','b',...,'z']
    if sys.version_info.major == 2:
        init_argumentnames_without_self = inspect.getargspec(func).args[1:]
    else:
        init_argumentnames_without_self = tuple(inspect.signature(func).parameters.keys())[1:]

    positional_values = args
    keyword_values_in_correct_order = tuple(kws[key] for key in init_argumentnames_without_self if key in kws)
    attribute_values = positional_values + keyword_values_in_correct_order

    for attribute_name,attribute_value in zip(init_argumentnames_without_self,attribute_values):
        setattr(self,attribute_name,attribute_value)

    # call the original __init__
    func(self, *args, **kws)


class Test():
    @simple_init
    def __init__(self,a,b,c,d=4):
        print(self.a,self.b,self.c,self.d)

#prints 1 3 2 4
t = Test(1,c=2,b=3)
#keeps signature
#prints ['self', 'a', 'b', 'c', 'd']
if sys.version_info.major == 2:
    print(inspect.getargspec(Test.__init__).args)
else:
    print(inspect.signature(Test.__init__))

Edit: If you have python 3.7+ just use dataclasses

A decorator solution that keeps the signature:

import decorator
import inspect
import sys


@decorator.decorator
def simple_init(func, self, *args, **kws):
    """
    @simple_init
    def __init__(self,a,b,...,z)
        dosomething()

    behaves like

    def __init__(self,a,b,...,z)
        self.a = a
        self.b = b
        ...
        self.z = z
        dosomething()
    """

    #init_argumentnames_without_self = ['a','b',...,'z']
    if sys.version_info.major == 2:
        init_argumentnames_without_self = inspect.getargspec(func).args[1:]
    else:
        init_argumentnames_without_self = tuple(inspect.signature(func).parameters.keys())[1:]

    positional_values = args
    keyword_values_in_correct_order = tuple(kws[key] for key in init_argumentnames_without_self if key in kws)
    attribute_values = positional_values + keyword_values_in_correct_order

    for attribute_name,attribute_value in zip(init_argumentnames_without_self,attribute_values):
        setattr(self,attribute_name,attribute_value)

    # call the original __init__
    func(self, *args, **kws)


class Test():
    @simple_init
    def __init__(self,a,b,c,d=4):
        print(self.a,self.b,self.c,self.d)

#prints 1 3 2 4
t = Test(1,c=2,b=3)
#keeps signature
#prints ['self', 'a', 'b', 'c', 'd']
if sys.version_info.major == 2:
    print(inspect.getargspec(Test.__init__).args)
else:
    print(inspect.signature(Test.__init__))

better explanation how it works

Source Link

edited Feb 12, 2016 at 8:01

Siphor

2.5k
2
14
10

A decorator solution that keeps the signature:

import decorator
import inspect
import sys


@decorator.decorator
def simple_init(func, self, *args, **kws):
    """
    @simple_init
    def __init__(self,a,b,...,z)
        dosomething()

    behaves like

    def __init__(self,a,b,...,z)
        self.a = a
        self.b = b
        ...
        self.z = z
        dosomething()
    """

    #init_argumentnames_without_self = ['a','b',...,'z']
    if sys.version_info.major == 2:
        parameter_namesinit_argumentnames_without_self = inspect.getargspec(func).args[1:]
    else:
        parameter_namesinit_argumentnames_without_self = tuple(inspect.signature(func).parameters.keys())[1:]
  
   for name,valuepositional_values in= zip(parameter_names,args 
 +   keyword_values_in_correct_order = tuple(kws[key] for key in parameter_namesinit_argumentnames_without_self if key in kws)
    attribute_values = positional_values + keyword_values_in_correct_order

    for attribute_name,attribute_value in zip(init_argumentnames_without_self,attribute_values):
        setattr(self,nameattribute_name,valueattribute_value) 

    # call the original __init__
    func(self, *args, **kws)


class Test():
    @simple_init
    def __init__(self,a,b,c,d=4):
        print(self.a,self.b,self.c,self.d)

#prints 1 3 2 4
t = Test(1,c=2,b=3)
#keeps signature
#prints (self['self', a'a', b'b', c)'c', 'd']
if sys.version_info.major == 2:
    print(inspect.getargspec(Test.__init__).args)
else:
    print(inspect.signature(Test.__init__))

A decorator solution that keeps the signature:

import decorator
import inspect
import sys


@decorator.decorator
def simple_init(func, self, *args, **kws):
    if sys.version_info.major == 2:
        parameter_names = inspect.getargspec(func).args[1:]
    else:
        parameter_names = tuple(inspect.signature(func).parameters.keys())[1:]
    for name,value in zip(parameter_names,args + tuple(kws[key] for key in parameter_names if key in kws)):
        setattr(self,name,value)
    # call the original __init__
    func(self, *args, **kws)


class Test():
    @simple_init
    def __init__(self,a,b,c):
        print(self.a,self.b,self.c)

#prints 1 3 2
t = Test(1,c=2,b=3)
#keeps signature
#prints (self, a, b, c)
if sys.version_info.major == 2:
    print(inspect.getargspec(Test.__init__).args)
else:
    print(inspect.signature(Test.__init__))

A decorator solution that keeps the signature:

import decorator
import inspect
import sys


@decorator.decorator
def simple_init(func, self, *args, **kws):
    """
    @simple_init
    def __init__(self,a,b,...,z)
        dosomething()

    behaves like

    def __init__(self,a,b,...,z)
        self.a = a
        self.b = b
        ...
        self.z = z
        dosomething()
    """

    #init_argumentnames_without_self = ['a','b',...,'z']
    if sys.version_info.major == 2:
        init_argumentnames_without_self = inspect.getargspec(func).args[1:]
    else:
        init_argumentnames_without_self = tuple(inspect.signature(func).parameters.keys())[1:]
 
    positional_values = args 
    keyword_values_in_correct_order = tuple(kws[key] for key in init_argumentnames_without_self if key in kws)
    attribute_values = positional_values + keyword_values_in_correct_order

    for attribute_name,attribute_value in zip(init_argumentnames_without_self,attribute_values):
        setattr(self,attribute_name,attribute_value) 

    # call the original __init__
    func(self, *args, **kws)


class Test():
    @simple_init
    def __init__(self,a,b,c,d=4):
        print(self.a,self.b,self.c,self.d)

#prints 1 3 2 4
t = Test(1,c=2,b=3)
#keeps signature
#prints ['self', 'a', 'b', 'c', 'd']
if sys.version_info.major == 2:
    print(inspect.getargspec(Test.__init__).args)
else:
    print(inspect.signature(Test.__init__))

fixed for 2.7

Source Link

edited Feb 4, 2016 at 14:46

Siphor

2.5k
2
14
10

A decorator solution that keeps the signature:

import decorator
import inspect
import sys


@decorator.decorator
def simple_init(func, self, *args, **kws):
    if sys.version_info.major == 2:
        parameter_names = inspect.getargspec(func).args[1:]
    else:
        parameter_names = tuple(inspect.signature(func).parameters.keys())[1:]
    for name,value in zip(parameter_names,args + tuple(kws[key] for key in parameter_names if key in kws)):
        setattr(self,name,value)
    # call the original __init__
    func(self, *args, **kws)


class Test():
    @simple_init
    def __init__(self,a,b,c):
        print(self.a,self.b,self.c)

#prints 1 3 2
t = Test(1,c=2,b=3)
#keeps signature
#prints (self, a, b, c)
if sys.version_info.major == 2:
    print(inspect.signaturegetargspec(Test.__init__).args)
#printselse:
 (self, a, b, cprint(inspect.signature(Test.__init__))

A decorator solution that keeps the signature:

import decorator
import inspect

@decorator.decorator
def simple_init(func, self, *args, **kws):
    parameter_names = tuple(inspect.signature(func).parameters.keys())[1:]
    for name,value in zip(parameter_names,args + tuple(kws[key] for key in parameter_names if key in kws)):
        setattr(self,name,value)
    # call the original __init__
    func(self, *args, **kws)


class Test():
    @simple_init
    def __init__(self,a,b,c):
        print(self.a,self.b,self.c)

#prints 1 3 2
t = Test(1,c=2,b=3)
#keeps signature
print(inspect.signature(Test.__init__))
#prints (self, a, b, c)

A decorator solution that keeps the signature:

import decorator
import inspect
import sys


@decorator.decorator
def simple_init(func, self, *args, **kws):
    if sys.version_info.major == 2:
        parameter_names = inspect.getargspec(func).args[1:]
    else:
        parameter_names = tuple(inspect.signature(func).parameters.keys())[1:]
    for name,value in zip(parameter_names,args + tuple(kws[key] for key in parameter_names if key in kws)):
        setattr(self,name,value)
    # call the original __init__
    func(self, *args, **kws)


class Test():
    @simple_init
    def __init__(self,a,b,c):
        print(self.a,self.b,self.c)

#prints 1 3 2
t = Test(1,c=2,b=3)
#keeps signature
#prints (self, a, b, c)
if sys.version_info.major == 2:
    print(inspect.getargspec(Test.__init__).args)
else:
    print(inspect.signature(Test.__init__))

Source Link

created Feb 4, 2016 at 7:24

Siphor

2.5k
2
14
10

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