[Tutor] More or less final Chutes & Ladders

[spir]

On 01/04/2014 05:47 AM, Keith Winston wrote:
> Here is what I think will be about the final version of C and L. I
> rearranged it quite a bit (into 2 classes), fixed a bug or two, and
> generally cleaned it up a bit. I haven't really polished it, but hopefully
> it will be less difficult to read... which is to say, if anyone wants to go
> through it AGAIN (at your leisure) I would appreciate comments on style,
> etc.

A few notes:

* You don't need, for lists, names likes 'self.chutes_list': 'self.chutes' does 
the job and is de facto standard in Python. Similarly, for a dict like one 
mapping names to phones, one can use 'names_phones' (read: "names' phones" or 
"names to phones").

* Try to find a satisfying personal convention (there is no standard in Python) 
for indexes (number of A thing) and counts (numbers of things), which constantly 
come up programming. (I use i_thing & n_things, or just i & n when in context 
there is no possible ambiguity.)

* What is the point of method reset apart from __init__? (Even if you need to 
reset a game after it has started, you could call __init__ for that. Rarely 
needed, but happens, esp. in games when eg a trap or bad luck brings the player 
back to start.)

* Make a class for results (see example below). Not only it is semantically 
correct (a result is a composite object, not a collection, but youy use a list), 
not only it makes code cleaner, but it allows more simply modifying and 
extending. Also, you could add there, directly in the concerned class, methods 
that deal with results (in addition to ones for result output, as in the 
example, which I also write first).

* When posting code, place your signature (-- Keith) _after_. Else, it causes 
weird bugs in email readers (eg mine, Thunderbird); I cannot even copy-paste it, 
for some weird reason.

Denis

=== class Result example ==============================

class Result:
     ''' result of an individual game

     Fields:
     * no        : 'numéro' (?) of the game
     * n_moves   : number of moves
     * chutes    : list of chute positions
     * ladders   : list of ladder positions

     Methods:
     * __repr__  : notation, as in code
     * __str__   : writing with field names
     '''
     def __init__ (self, no, n_moves, chutes, ladders):
         ''' Store game stat data. '''
         self.no         = no
         self.n_moves    = n_moves
         self.chutes     = chutes
         self.ladders    = ladders

     # output
     def __repr__ (self):
         ''' notation, as in code (for programme feedback) '''
         return "Result(%r, %r, %r, %r)" % \
             (self.no, self.n_moves, self.chutes, self.ladders)
     def __str__ (self):
         ''' writing with field names (eg for user info in UI) '''
         return "{no:%s  n-moves:%s  chutes:%s  ladders:%s}" % \
             (self.no, self.n_moves, self.chutes, self.ladders)

# fake example
res = Result(3, 333, [1,2,3], [99,33,11])
print("\n%r\n\n%s\n" %(res, res))

""" writes out:

Result(3, 333, [1, 2, 3], [99, 33, 11])

{no:3  n-moves:333  chutes:[1, 2, 3]  ladders:[99, 33, 11]}

"""