Python Introspection

Contents

• sys modules
• 查詢 Object
  • Type
  • Attributes
  • Callable
  • Class 相關

sys modules

• 查詢目前所在的作業系統 (OS)

>>> import sys
>>> sys.platform
'darwin'

• Max Int

>>> sys.maxint
2147483647

• 目前已經讀取的 modules (sys.modules)

查詢 Object

• 名字 (name)

>>> dir.__name__
'dir'

Type

查詢物件的 type

>>> type('e')
<type 'str'>

比較 type

>>> type('a') is types.StringType
True

Attributes

hasattr(object, name) getattr(object, name [,default])

>>> hasattr(id,'__doc__')
True
>>> print getattr(id,'__doc__')
id(object) -> integer

Return the identity of an object.  This is guaranteed to be unique among
simultaneously existing objects.  (Hint: it's the object's memory address.)

Callable

判斷是否能呼叫

>>> callable(dir)
True

Class 相關

>>> print isinstance.__doc__
isinstance(object, class-or-type-or-tuple) -> bool

Return whether an object is an instance of a class or of a subclass thereof.
With a type as second argument, return whether that is the object's type.
The form using a tuple, isinstance(x, (A, B, ...)), is a shortcut for
isinstance(x, A) or isinstance(x, B) or ... (etc.).
>>> print isinstance.__doc__
isinstance(object, class-or-type-or-tuple) -> bool

Return whether an object is an instance of a class or of a subclass thereof.
With a type as second argument, return whether that is the object's type.
The form using a tuple, isinstance(x, (A, B, ...)), is a shortcut for
isinstance(x, A) or isinstance(x, B) or ... (etc.).