On 2007-01-15, Gabriel Genellina <[EMAIL PROTECTED]> wrote:
> At Monday 15/1/2007 17:45, Stef Mientki wrote:
>
>>Is there some handy/ nice manner to view the properties of some variable ?
>>As a newbie, I often want to see want all the properties of a var,
>>and also some corner values (large arrays) etc.
>
> You can try dir(x), vars(x). If you want a "nice print", see
> the pprint module.
>
> py> import csv
> py> x = csv.DictReader('') # a bogus object
> py> x
><csv.DictReader instance at 0x00BC79B8>
> py> dir(x)
> ['__doc__', '__init__', '__iter__', '__module__', 'fieldnames',
> 'next', 'reader'
> , 'restkey', 'restval']
> py> vars(x)
> {'restkey': None, 'restval': None, 'fieldnames': None, 'reader':
><_csv.reader ob
> ject at 0x00BC98B8>}
> py> from pprint import pprint
> py> pprint(vars(x))
> {'fieldnames': None,
> 'reader': <_csv.reader object at 0x00BC98B8>,
> 'restkey': None,
> 'restval': None}
> py>
It's an unfortunately limited sort of introspection. To rehash a
recent experience:
>>> import re
>>> import pprint
>>> r = re.match("(x+)|(y+)", "xxx")
>>> pprint.pprint(dir(r))
['__copy__',
'__deepcopy__',
'end',
'expand',
'group',
'groupdict',
'groups',
'span',
'start']
>>> r.lastindex
1
The documentation is deliberately vague:
dir( [object])
[...] The list is not necessarily
complete. If the object is a module object, the list contains
the names of the module's attributes. If the object is a type
or class object, the list contains the names of its attributes,
and recursively of the attributes of its bases. Otherwise, the
list contains the object's attributes' names, the names of its
class's attributes, and recursively of the attributes of its
class's base classes. The resulting list is sorted
alphabetically. [...]
It's unclear to me what attributes an object could have that
aren't included in the above list.
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.
In other words, dir is just for fun, like monkey bars. ;)
--
Neil Cerutti
The eighth-graders will be presenting Shakespeare's Hamlet in the church
basement on Friday at 7 p.m. The congregation is invited to attend this
tragedy. --Church Bulletin Blooper
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