element in dict

I have a dict as below:

v0 = {(7, 3): '7', (4, 7): '*', (1, 3): '*', (6, 6): '*', (3, 0):
'2', (2, 8): '*', (8, 0): '3', (7, 8): '*', (5, 4): '*', (2, 1):
'*', (5, 6): '4', (6, 2): '*', (1, 6): '*', (3, 7): '*', (5, 1):
'*', (0, 3): '4', (8, 5): '2', (2, 5): '*', (7, 2): '*', (4, 0):
'*', (1, 2): '2', (3, 8): '6', (6, 7): '*', (3, 3): '1', (0, 6):
'*', (8, 1): '*', (7, 6): '5', (4, 4): '4', (6, 3): '*', (1, 5):
'1', (5, 8): '3', (5, 0): '6', (2, 2): '*', (8, 6): '*', (3, 5):
'*', (4, 1): '*', (1, 1): '*', (6, 4): '*', (3, 2): '7', (0, 0):
'*', (8, 2): '*', (2, 7): '4', (7, 1): '2', (4, 5): '*', (0, 4):
'2', (6, 0): '*', (1, 4): '7', (7, 7): '*', (5, 5): '7', (7, 5):
'*', (2, 3): '*', (0, 7): '*', (8, 7): '7', (6, 8): '*', (4, 2):
'*', (1, 0): '*', (0, 8): '5', (5, 7): '*', (6, 5): '*', (5, 3):
'*', (0, 1): '1', (8, 3): '*', (7, 0): '1', (4, 6): '*', (3, 6):
'*', (3, 4): '*', (6, 1): '7', (3, 1): '*', (2, 6): '*', (2, 4):
'*', (7, 4): '3', (2, 0): '*', (1, 8): '9', (8, 8): '*', (4, 3):
'*', (1, 7): '3', (0, 5): '*', (4, 8): '*', (5, 2): '*', (0, 2):
'*', (8, 4): '8'}

Is there a 开发者_Go百科way I can retrieve any particular key of my interest?

Say for example, I will give an input 7 & 0 to my function and it should get me the result:

1.

Or if I give 8 & 4 it should get me 8.

I'm trying to learn Python. Anything to help me solve my question be greatly appreciated.

Thanks.

---

Have you tried this?

>>> v0[(7,3)]
'7'
>>> v0[(7,0)]
'1'

Or in a function:

>>> def retr(x, y):
...     return v0[(x, y)]
... 
>>> retr(8,4)
'8'

EDIT:

Technically speaking, you do not have to use the parentheses within the braces, but it does make it clearer that the dictionary key is in fact a single tuple.

>>> v0[7,0]
'1'

---

Yes of course, that's what a dictionary is! if your dictionary is called v0 then you just use v0[(7,0)] or v0[(8,4)]

In this case, (7,0) and (8,4) are the "keys" and what they map to, e.g. 1 and 8, respectively, are the "values" of a dictionary. A dictionary is useful for storing values when you want to retrieve them by key, just like you're doing now.

---

the great thing in dictionaries is that you always work with key value pairs, i.e. (7, 0) is your key and 1 is the value corresponding to it. So you can access the value by calling

value = v0[key]

which is, for your example

value = v0[(7, 0)]

and value will have the value 1 after that operation.

See here for more information about dictionaries.

---

And they looked like coordinates to me. If you are trying to represent a matrix, use a multi-dimensional array instead of a dictionary. It's easier to use, and also a faster solution.

For multi-dimensional arrays, follow that link: http://www.linuxtopia.org/online_books/programming_books/python_programming/python_ch20s05.html