problems with Methods in Python 3.4.2
Terry Reedy
tjreedy at udel.edu
Thu Dec 18 15:59:33 EST 2014
On 12/18/2014 12:27 PM, Marcus Lütolf wrote:
Learn to use dir to fine valid names.
> 1)I am trying to do this:
>
> >>> dir(_builtins_)
>
> I am getting this:
>
> Traceback (most recent call last):
>
> File "<pyshell#0>", line 1, in <module>
>
> dir(_builtins_)
>
> NameError: name '_builtins_' is not defined
>>> dir()
['__builtins__', '__doc__', '__loader__', '__name__', '__package__',
'__spec__']
shows the defined names.
> 2)I am trying to do this:
>
>>>> 'TTA',_add_('GGA')
>
> I’am getting this :
>
> Traceback (most recent call last):
>
> File "<pyshell#0>", line 1, in <module>
>
> 'TTA',_add_('GGA')
>
> NameError: name '_add_' is not defined
>>> dir('a') shows string attribute names
> 3)I am trying to do this:
>
>>>> -3 .abs()
>
> I’am getting this
>
> Traceback (most recent call last):
>
> File "<pyshell#1>", line 1, in <module>
>
> -3 .abs()
>
> AttributeError: 'int' object has no attribute 'abs'
dir(3) shows int attributes
> 4) finally, after printing
>
> >>>abs._doc_()
>
> I am getting this (and so on) :
>
> Traceback (most recent call last):
>
> File "<pyshell#2>", line 1, in <module>
>
> abs._doc_()
>
> AttributeError: 'builtin_function_or_method' object has no attribute '_doc_'
dir(abs) ditto
> What did I do wrong ?
You did not use the interactive help already available. help(<object>)
is also very useful.
--
Terry Jan Reedy
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