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Re: How can I verify if the content of a variable is a list or a string?

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  Re: How can I verify if the content of a variable is a list or a string? Terry Reedy <tjreedy@udel.edu> - 2012-01-31 19:56 -0500
    Re: How can I verify if the content of a variable is a list or a string? Rainer Grimm <r.grimm@science-computing.de> - 2012-02-01 23:19 -0800
    Re: How can I verify if the content of a variable is a list or a string? Rainer Grimm <r.grimm@science-computing.de> - 2012-02-01 23:19 -0800
      Re: How can I verify if the content of a variable is a list or a string? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-02-02 07:31 +0000

#19669 — Re: How can I verify if the content of a variable is a list or a string?

On 1/31/2012 7:44 PM, Andres Soto wrote:
> Hi,
> I'm writing a function which receive a list which elements are strings
> or new lists (sublists) containing strings.
> How can I verify if sone element of the list (which is contained in a
> variable) is a list or a string?
> I found the method isinstance(object,class) but I don't know which class
> should I use for.

For 3.x, 'list' or 'str' (where 'str' means unicode). For 2.x, I believe 
'basestring' includes unicode strings as well as byte strings.

 >>> isinstance([], list)
True
 >>> isinstance([], str)
False

-- 
Terry Jan Reedy

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#19772

You can do it more concise.

>>> def isListOrString(p):
...    return any((isinstance(p,list),isinstance(p,str)))
...
>>> listOrString("string")
True
>>> listOrString([1,2,3])
True
>>> listOrString(2)
False
>>> listOrString(False)
False

Rainer

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#19773

You can do it more concise.

>>> def isListOrString(p):
...    return any((isinstance(p,list),isinstance(p,str)))
...
>>> listOrString("string")
True
>>> listOrString([1,2,3])
True
>>> listOrString(2)
False
>>> listOrString(False)
False

Rainer

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#19776

On Wed, 01 Feb 2012 23:19:57 -0800, Rainer Grimm wrote:

> You can do it more concise.
> 
>>>> def isListOrString(p):
> ...    return any((isinstance(p,list),isinstance(p,str)))


Or even more concisely still:

isinstance(p, (list, str))



-- 
Steven

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