Dictionaries
Gary Herron
gary.herron at islandtraining.com
Sun Feb 9 02:18:56 EST 2014
On 02/08/2014 11:07 PM, worthingtonclinton at gmail.com wrote:
> why in a for loop can i access values for a dict that i did not address in the for loop.
>
> example:
>
> a = {blah:blah}
> b = {blah:blah}
>
> for x in a:
>
> print a[x]
>
> #here's what i don't understand
>
> print b[x]
>
> # it would print the value for dict b even though it wasn't called upon in the for loop!
>
>
> Thanks in advance.
The lookup of a value in dictionary b does not care where the index
comes from. Quite simply, x has the value of 'blah', and b has 'blah'
as a key, so b[x] works.
If a and b had different keys, then you would get an error:
>>> a = {'a':1}
>>> b = {'b':2}
>>> for x in a:
... print x
... print a[x]
... print b[x]
...
a
1
Traceback (most recent call last):
File "<stdin>", line 4, in <module>
KeyError: 'a'
Gary Herron
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