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如何在Python中获得类引用的具体名称(例如“<module\u name>”、“<class\u name”>)?

class python

1

Sam Dolan · 技术社区 · 15 年前

到目前为止,我的情况是:

def get_concrete_name_of_class(klass):
"""Given a class return the concrete name of the class.

klass - The reference to the class we're interested in.
"""

# TODO: How do I check that klass is actually a class?
# even better would be determine if it's old style vs new style
# at the same time and handle things differently below.

# The str of a newstyle class is "<class 'django.forms.CharField'>"
# so we search for the single quotes, and grab everything inside it,
# giving us "django.forms.CharField"
matches = re.search(r"'(.+)'", str(klass))
if matches:
    return matches.group(1)

# Old style's classes' str is the concrete class name.
return str(klass)

所以这个方法很好用,但是对类的字符串进行正则表达式搜索似乎很不成熟。注意我不能就这么做 klass().__class__.__name__ (无法处理args等)。

还有,有人知道如何完成TODO(检查 klass 是一个类,它是旧样式还是新样式?

根据这些评论,我的结论是:

def get_concrete_name_of_class(klass):
    """Given a class return the concrete name of the class.

    klass - The reference to the class we're interested in.

    Raises a `TypeError` if klass is not a class.
    """

    if not isinstance(klass, (type, ClassType)):
        raise TypeError('The klass argument must be a class. Got type %s; %s' % (type(klass), klass))

    return '%s.%s' % (klass.__module__, klass.__name__)

3 回复 | 直到 15 年前

1

2

Ned Batchelder 15 年前

klass.__name__ ,或获取完全限定名, klass.__module__+'.'+klass.__name__ ?

2

Eli Courtwright 15 年前

你可以说

klass.__module__ + "." + klass.__name__

至于如何判断某个类是旧类还是新类,我建议说

from types import ClassType  # old style class type

if not isinstance(klass, (type, ClassType)):
    # not a class
elif isinstance(klass, type):
    # new-style class
else:
    # old-style class

3

1

S.Lott 15 年前

>>> class X:
...     pass
... 
>>> class Y( object ):
...     pass
...

type函数告诉您名称是类还是旧样式还是新样式。

>>> type(X)
<type 'classobj'>
>>> type(Y)
<type 'type'>

它还告诉你一个物体是什么。

>>> x= X()
>>> type(x)
<type 'instance'>
>>> y= Y()
>>> type(y)
<class '__main__.Y'>

你可以通过简单的询问它是什么的子类来测试旧样式和新样式。

>>> issubclass(y.__class__,object)
True
>>> issubclass(x.__class__,object)
False
>>>