Python dir() function with regex filtering options

Question

dir() returns a list of all the names, comprising the attributes of the given object and of attributes reachable from it

But, I want the ability to regex filter the results of dir() in a simple manner, similar to the unix grep tool

>>> dir(list)
['__add__', '__class__', '__contains__', ...... ,'remove', 'reverse', 'sort']

The above returns a huge list of attributes, and some of then have been hidden for brevity.

>>> # How can I do something like this, which allows me to reduce the list.
>>> dir(list,filter='<regular-expression>')

Example:

>>> dir(list,'in')
['__contains__', '__init__', 'index', 'insert']

All the filtered elements have the attributes have the expression "in" within them.

How can I achieve this kind of regular-expression based filtering with the python dir() function or something similar?

score 2 · Answer 1 · answered Aug 01 '14 at 12:32

2

A list comprehension is the simplest way

>>> [a for a in dir(list) if re.match(r'__\w{,2}__',a)]
['__eq__', '__ge__', '__gt__', '__le__', '__lt__', '__ne__']

answered Aug 01 '14 at 12:32

ivan_pozdeev

33,874
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score 1 · Answer 2 · answered Aug 01 '14 at 12:05

1

>>> [a for a in dir(list) if 'in' in a]
['__contains__', '__init__', 'index', 'insert']

answered Aug 01 '14 at 12:05

Armali

18,255
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the question was about a regex – ivan_pozdeev Aug 01 '14 at 12:27

score 0 · Answer 3 · answered Jul 14 '13 at 20:50

Don't forget about help:

>>> help(list)
Help on class list in module __builtin__:

class list(object)
 |  list() -> new empty list
 |  list(iterable) -> new list initialized from iterable's items
 |  
 |  Methods defined here:
 |  
 |  __add__(...)
 |      x.__add__(y) <==> x+y
 |  
 |  __contains__(...)
 |      x.__contains__(y) <==> y in x
 |  
 |  __delitem__(...)
 |      x.__delitem__(y) <==> del x[y]
 |  
 |  __delslice__(...)
 |      x.__delslice__(i, j) <==> del x[i:j]
 |      
 |      Use of negative indices is not supported.
 |  
 |  __eq__(...)
 |      x.__eq__(y) <==> x==y
 |  
 |  __ge__(...)
 |      x.__ge__(y) <==> x>=y
 |  
 |  __getattribute__(...)
 |      x.__getattribute__('name') <==> x.name
 |  
 |  __getitem__(...)
 |      x.__getitem__(y) <==> x[y]
 |  
 |  __getslice__(...)
 |      x.__getslice__(i, j) <==> x[i:j]
 |      
 |      Use of negative indices is not supported.
 |  
 |  __gt__(...)
 |      x.__gt__(y) <==> x>y
 |  
 |  __iadd__(...)
 |      x.__iadd__(y) <==> x+=y
 |  
 |  __imul__(...)
 |      x.__imul__(y) <==> x*=y
 |  
 |  __init__(...)
 |      x.__init__(...) initializes x; see x.__class__.__doc__ for signature
 |  
 |  __iter__(...)
 |      x.__iter__() <==> iter(x)
 |  
 |  __le__(...)
 |      x.__le__(y) <==> x<=y
 |  
 |  __len__(...)
 |      x.__len__() <==> len(x)
 |  
 |  __lt__(...)
 |      x.__lt__(y) <==> x<y
 |  
 |  __mul__(...)
 |      x.__mul__(n) <==> x*n
 |  
 |  __ne__(...)
 |      x.__ne__(y) <==> x!=y
 |  
 |  __repr__(...)
 |      x.__repr__() <==> repr(x)
 |  
 |  __reversed__(...)
 |      L.__reversed__() -- return a reverse iterator over the list
 |  
 |  __rmul__(...)
 |      x.__rmul__(n) <==> n*x
 |  
 |  __setitem__(...)
 |      x.__setitem__(i, y) <==> x[i]=y
 |  
 |  __setslice__(...)
 |      x.__setslice__(i, j, y) <==> x[i:j]=y
 |      
 |      Use  of negative indices is not supported.
 |  
 |  __sizeof__(...)
 |      L.__sizeof__() -- size of L in memory, in bytes
 |  
 |  append(...)
 |      L.append(object) -- append object to end
 |  
 |  count(...)
 |      L.count(value) -> integer -- return number of occurrences of value
 |  
 |  extend(...)
 |      L.extend(iterable) -- extend list by appending elements from the iterable
 |  
 |  index(...)
 |      L.index(value, [start, [stop]]) -> integer -- return first index of value.
 |      Raises ValueError if the value is not present.
 |  
 |  insert(...)
 |      L.insert(index, object) -- insert object before index
 |  
 |  pop(...)
 |      L.pop([index]) -> item -- remove and return item at index (default last).
 |      Raises IndexError if list is empty or index is out of range.
 |  
 |  remove(...)
 |      L.remove(value) -- remove first occurrence of value.
 |      Raises ValueError if the value is not present.
 |  
 |  reverse(...)
 |      L.reverse() -- reverse *IN PLACE*
 |  
 |  sort(...)
 |      L.sort(cmp=None, key=None, reverse=False) -- stable sort *IN PLACE*;
 |      cmp(x, y) -> -1, 0, 1
 |  
 |  ----------------------------------------------------------------------
 |  Data and other attributes defined here:
 |  
 |  __hash__ = None
 |  
 |  __new__ = <built-in method __new__ of type object>
 |      T.__new__(S, ...) -> a new object with type S, a subtype of T

Python dir() function with regex filtering options

3 Answers3