What meaning of this ""hello %s you are %s years old" % x"

Gary Herron gary.herron at islandtraining.com
Sun Jul 27 22:02:18 CEST 2014


On 07/27/2014 11:49 AM, fl wrote:
> Hi,
>
> I get a post on tuple, see below please, on line. It seems that something is
> missing. I want to learn tuple from this example as well.
>
> Could you explain it to me (a tuple % another tuple)?
>
>
> Thanks,
>
>
>
>
>
>
> http://stackoverflow.com/questions/1708510/python-list-vs-tuple-when-to-use-each
>
> In Python, when should you use lists and when tuples?
>
> Sometimes you don't have a choice, for example if you have
>
> "hello %s you are %s years old" % x
> then x must be a tuple.
>
> But if I am the one who designs the API and gets to choose the data types, then
> what are the guidelines?

That's not tuple%tuple, but rather string%tuple.  And string%tuple is 
the older method of formatting an output string from a template and a 
tuple of values.  See 
https://docs.python.org/2/library/stdtypes.html#string-formatting for 
details.

However, if you are just learning Python, you should probably use the 
*newer* formatting operations.  See 
https://docs.python.org/3.3/library/string.html#formatspec for details 
of that.

Gary Herron




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