Python中是否有一个函数列出特定对象的属性和方法？

Question

Is there a function in Python to list the attributes and methods of a particular object?

Something like:

ShowAttributes ( myObject )

   -> .count
   -> .size

ShowMethods ( myObject )

   -> len
   -> parse

Answer 1

You want to look at the dir() function:

>>> li = []
>>> dir(li)      
['append', 'count', 'extend', 'index', 'insert',
'pop', 'remove', 'reverse', 'sort']

li is a list, so dir(li) returns a list of all the methods of a list. Note that the returned list contains the names of the methods as strings, not the methods themselves.

---

Edit in response to comment:

No this will show all inherited methods as well. Consider this example:

test.py:

class Foo:
    def foo(): pass

class Bar(Foo):
    def bar(): pass

Python interpreter:

>>> from test import Foo, Bar
>>> dir(Foo)
['__doc__', '__module__', 'foo']
>>> dir(Bar)
['__doc__', '__module__', 'bar', 'foo']

---

You should note that Python's documentation states:

Note: Because dir() is supplied primarily as a convenience for use at an interactive prompt , it tries to supply an interesting set of names more than it tries to supply a rigorously or consistently defined set of names, and its detailed behavior may change across releases . For example, metaclass attributes are not in the result list when the argument is a class.

Therefore it's not safe to use in your code. Use vars() instead. Vars() doesn't include information about the superclasses, you'd have to collect them yourself.

---

If you're using dir() to find information in an interactive interpreter, consider the use of help() .

Answer 2

dir（）和vars（）不适合你吗？

Answer 3

and for a more human-readable way, you can use see :

In [1]: from see import see
In [2]: x = "hello world!"
In [3]: see(x)
Out[3]: 
  []   in   +   *   %   <   <=   ==   !=   >   >=   hash()   help()   len()
  repr()   str()   .capitalize()   .center()   .count()   .decode()
  .encode()   .endswith()   .expandtabs()   .find()   .format()   .index()
  .isalnum()   .isalpha()   .isdigit()   .islower()   .isspace()   .istitle()
  .isupper()   .join()   .ljust()   .lower()   .lstrip()   .partition()
  .replace()   .rfind()   .rindex()   .rjust()   .rpartition()   .rsplit()
  .rstrip()   .split()   .splitlines()   .startswith()   .strip()
  .swapcase()   .title()   .translate()   .upper()   .zfill()

Answer 4

Another way to do this is with the nifty IPython environment. It lets you tab complete to find all the methods and fields of an object.

Answer 5

令我惊讶的是，没有人提到python对象函数：
keys()