我正在尝试从类中的方法动态创建模块级函数。因此，对于类中的每个方法，我想创建一个具有相同名称的函数，该函数创建该类的实例，然后调用该方法。
我想这样做的原因是我可以采用面向对象的方法来创建 Fabric 文件。由于 Fabric 将调用模块级函数而不是类的方法，这是我的解决方法。
我已使用以下链接开始使用
我想出了以下代码
import inspect
import sys
import types
class TestClass(object):
def __init__(self):
pass
def method1(self, arg1):
print 'method 1 %s' % arg1
def method2(self):
print 'method 2'
def fabric_class_to_function_magic(module_name):
# get the module as an object
print module_name
module_obj = sys.modules[module_name]
print dir(module_obj)
# Iterate over the methods of the class and dynamically create a function
# for each method that calls the method and add it to the current module
for method in inspect.getmembers(TestClass, predicate=inspect.ismethod):
print
print method
method_name, method_obj = method
# create a new template function which calls the method
def newfunc_template(*args, **kwargs):
tc = TestClass()
func = getattr(tc, method_name)
return func(*args, **kwargs)
# create the actual function
print 'code: ', newfunc_template.func_code
print 'method_name: ', method_name
newfunc = types.FunctionType(newfunc_template.func_code,
{'TestClass': TestClass,
'getattr': getattr,
'method_name': method_name,
},
name=method_name,
argdefs=newfunc_template.func_defaults,
closure=newfunc_template.func_closure,
)
# add the new function to the current module
setattr(module_obj, method_name, newfunc)
# test the dynamically created module level function
thismodule = sys.modules[__name__]
print dir(thismodule)
fabric_class_to_function_magic(__name__)
print dir(thismodule)
method1('arg1')
method2()
我收到以下错误
['TestClass', '__builtins__', '__doc__', '__file__', '__name__', '__package__', 'fabric_class_to_function_magic', 'inspect', 'sys', 'thismodule', 'types']
__main__
['TestClass', '__builtins__', '__doc__', '__file__', '__name__', '__package__', 'fabric_class_to_function_magic', 'inspect', 'sys', 'thismodule', 'types']
('__init__', <unbound method TestClass.__init__>)
code: <code object newfunc_template at 0x7f8800a28d50, file "test.py", line 85>
method_name: __init__
('method1', <unbound method TestClass.method1>)
code: <code object newfunc_template at 0x7f8800a28d50, file "test.py", line 85>
method_name: method1
('method2', <unbound method TestClass.method2>)
code: <code object newfunc_template at 0x7f8800a28d50, file "test.py", line 85>
method_name: method2
['TestClass', '__builtins__', '__doc__', '__file__', '__init__', '__name__', '__package__', 'fabric_class_to_function_magic', 'inspect', 'method1', 'method2', 'sys', 'thismodule', 'types']
Traceback (most recent call last):
File "test.py", line 111, in <module>
method1('arg1')
File "test.py", line 88, in newfunc_template
return func(*args, **kwargs)
TypeError: method2() takes exactly 1 argument (2 given)
好像是重用了函数的引用？有什么想法吗？
更新：这是经过 Ned Batchelder 修复后的工作代码
def fabric_class_to_function_magic(module_name):
# get the module as an object
module_obj = sys.modules[module_name]
# Iterate over the methods of the class and dynamically create a function
# for each method that calls the method and add it to the current module
for method in inspect.getmembers(TestClass, predicate=inspect.ismethod):
method_name, method_obj = method
# get the bound method
tc = TestClass()
func = getattr(tc, method_name)
# add the function to the current module
setattr(module_obj, method_name, func)
更新2：这是我关于该主题的博客文章：http://www.saltycrane.com/blog/2010/09/class-based-fabric-scripts-metaprogramming-hack/
你的解决方案想得太多了。将
fabric_class_to_function_magic tc = TestClass()
func = getattr(tc, method_name)
# add the new function to the current module
setattr(module_obj, method_name, func)
而且效果很好。无需创建新的函数对象，您的对象上已经有 getattr 返回的函数对象。 getattr 返回的绑定方法是一个可调用的东西。只需将其分配给您的模块属性，就可以开始了。
实际上你的代码是正确的，但是当 return func(*args, **kwargs) 执行时，args 将传递像 () 这样的空元组，并且你的 method2 中没有参数，所以它引发了这样的异常，
解决您问题的快速解决方案是，例如
class TestClass(object):
def __init__(self):
pass
def method1(self, arg1):
print 'method 1 %s' % arg1
def method2(self, *args, **kw):
print 'method 2'
这可能对某人有用：
import inspect
import sys
def get_functions_from_class_in_module_and_extract_to_module(module, *args, class_config={}, **kwargs):
classes = dict(tuple(x) for x in inspect.getmembers(sys.modules[module.__name__], inspect.isclass))
for cls_name, cls in classes.items():
class_instance = cls(**class_config[cls_name])
functions = dict(tuple(x) for x in inspect.getmembers(cls, inspect.isfunction))
for function_name, func in functions.items():
class_func = lambda *args, **kwargs: func(class_instance, *args, **kwargs)
setattr(module, function_name, class_func)