John Carmona wrote:
> Kristian you wrote:
>
> ---------------------------------------------------------------------------------------------
>
> This assumes all input as integers; if you want months entered by
> name, you'll have to write a conversion routine (hint: use a dict).
> ---------------------------------------------------------------------------------------------
>
>
> I have been looking for a while about doing a conversion routine (using
> a dictionary??), are you saying that I should convert a string (January,
> February, etc.) into integers. Could you please give me some light (do
> not write the code please but just point me to the right direction if
> you can)
A dictionary is a data structure containing keys and values that defines
a mapping from each key to its corresponding value. You define it like this:
>>> squares = {1: 1, 10: 100, 4: 15, 5: 25}
Or an empty dictionary:
>>> emptydict = {}
Once defined, you can access individual elements via their keys:
>>> print squares[4]
15
This way you can also assign values to existing elements:
>>> squares[4] = 4*4
>>> print squares[4]
16
Or add new elements:
>>> squares[6] = 16
>>> squares[7] = 49
Python raises a KeyError exception if you try to read an element with a
non-existing key:
>>> print squares[9]
Traceback (most recent call last):
File "<pyshell#1>", line 1, in -toplevel-
print squares[9]
KeyError: 9
I used numbers for the keys and the values, but in fact any Python
object can be used as a value. Any immutable object can be used as a
key; for now, just remember that you can use numbers, strings and tuples
as keys.
So what you could do is create a dictionary with the names of the months
as keys and the corresponding numbers as values and use that dictionary
to convert the names in the numbers.
Try to play a bit with dictionaries in IDLE (or your Python shell of
choice). If anything's not clear, just give a yell.
--
If I have been able to see further, it was only because I stood
on the shoulders of giants. -- Isaac Newton
Roel Schroeven
_______________________________________________
Tutor maillist - Tutor@python.org
http://mail.python.org/mailman/listinfo/tutor
