类函数中的可选参数

Question

I am Trying to make a 2048 game in pygame using python. I want the function stackright and stackleft to operate on the self.data if no parameters are given, and return a stackrighted or stacklefted matrix if a matrix is given in the parameters.how would i go about doing this. I am using python 2.7 here is my code:

import random
def getnull(): # returns null matrix
    data = [
    [0,0,2,2],
    [0,4,0,2],
    [0,2,0,0],
    [2,0,2,0]
    ]
    return data

class Data:
    def fillrandom(self): #updates data by adding 2/4 randomly
        exit = False
        while not exit:
            y = random.randint(0,3)
            x = random.randint(0,3)
            if self.data[y][x] == 0:
                if random.randint(1,10) == 1:
                    self.data[y][x] = 4
                    exit = True
                else:
                    self.data[y][x] = 2
                    exit = True
    def alignright(self):   #
        list1 = [[],[],[],[]]
        for i in range(4):          # per row loop
            for count in range(4):   # per column loop
                if self.data[i][count] != 0:
                    list1[i] += [self.data[i][count]]
            list1[i] = [0]*(4-len(list1[i])) + list1[i]
        self.data = list1
    def alignleft(self):
        list1 = [[],[],[],[]]
        for i in range(4):          # per row loop
            for count in range(4):   # per column loop
                if self.data[i][count] != 0:
                    list1[i] += [self.data[i][count]]
            list1[i] = list1[i] + [0]*(4-len(list1[i]))
        self.data = list1
    def printstate(self):
        print(self.data[0])
        print(self.data[1])
        print(self.data[2])
        print(self.data[3])
        print("-------")
    def checkfilled(self):
        for count in range(4):
            for i in range(4):
                if self.data[count][i] == 0:
                    return False
        return True
    def stackright(self):
        for i in range(4):
            if self.data[i][3] == self.data[i][2]:
                if self.data[i][1] == self.data[i][0]:
                    self.data[i][3] = self.data[i][3] *2
                    self.score += self.data[i][3]
                    self.data[i][2] = self.data[i][1] *2
                    self.score += self.data[i][2]
                    self.data[i][0] , self.data[i][1] = 0,0
                else:
                    self.data[i][3] = self.data[i][3] *2
                    self.score += self.data[i][3]
                    self.data[i][2] = self.data[i][1]
                    self.data[i][1] = self.data[i][0]
                    self.data[i][0] = 0
            elif self.data[i][2] == self.data[i][1]:
                    self.data[i][2] = self.data[i][2] *2
                    self.score += self.data[i][2]
                    self.data[i][1] = self.data[i][0]
                    self.data[i][0] = 0
            elif self.data[i][1] == self.data[i][0]:
                self.data[i][1] = self.data[i][1] *2
                self.score += self.data[i][1]
                self.data[i][0] = 0
    def stackleft(self):
        for i in range(4):
            if self.data[i][0] == self.data[i][1]:
                if self.data[i][2] == self.data[i][3]:
                    self.data[i][0] = self.data[i][0] *2
                    self.score += self.data[i][0]
                    self.data[i][1] = self.data[i][2] *2
                    self.score += self.data[i][1]
                    self.data[i][3] , self.data[i][2] = 0,0
                else:
                    self.data[i][0] = self.data[i][0]*2
                    self.score += self.data[i][0]
                    self.data[i][1] = self.data[i][2]
                    self.data[i][2] = self.data[i][3]
                    self.data[i][3] = 0
            elif self.data[i][1] == self.data[i][2]:
                    self.data[i][1] = self.data[i][1] *2
                    self.score += self.data[i][1]
                    self.data[i][2] = self.data[i][3]
                    self.data[i][3] = 0
            elif self.data[i][2] == self.data[i][3]:
                self.data[i][2] = self.data[i][2] *2
                self.score += self.data[i][2]
                self.data[i][3] = 0
    def alignup(self):
        col = [[],[],[],[]]
        for i in range(4): #per col loop
            for count in range(4): #per row loop
                if self.data[count][i] != 0:
                    col[i] += [self.data[count][i]]
            col[i] = col[i] + [0]*(4-len(col[i]))
        for i in range(4):      # convert column to row
            for count in range(4):
                self.data[count][i] = col[i][count]
    def aligndown(self):
        col = [[],[],[],[]]
        for i in range(4): #per col loop
            for count in range(4): #per row loop
                if self.data[count][i] != 0:
                    col[i] += [self.data[count][i]]
            col[i] = [0]*(4-len(col[i])) + col[i]
        for i in range(4):       # convert column to row
            for count in range(4):
                self.data[count][i] = col[i][count]
    def __init__(self):
        self.data = getnull()
        self.score = 0
data = Data()
data.aligndown()
data.printstate()
print(data.score)



while True:
    pass

Answer 1

You can have default parameters. for example:

def func(self, matrix=None):
    if matrix is None:
        #do stuff with self.data
    else:
        #do stuff

That way if no parameters are given then the default value is None

So then you know that if the value of matrix is None then the caller hasn't specified a value so you do something with self.data . but if he does specify a value( else ) then it means that the caller specified a value and you could do something with the matrix.

Or if you want to use them as the same value you could do the following:

def func(self, matrix=None):
    if matrix is None: matrix = self.data
    #do stuff with the variable 'data'

Now data is whatever you want it to be

Answer 2

Something like this could do the trick:

def stackright(self, *args):
    if len(args) == 0:
        #do things with no arguments
    else:
        #do things with arguments
        print(args[0], args[1], ...)

You can also replace *args with **kwargs if you want to be able to call the parameters by their name. You can even use both:

def f(self, madatoryArgument1, mandatoryArgument2, *args, **kwargs)

The advantage of this over passing arguments with a None default value, is that it simplifies it when the number of arguments grows.

Answer 3

It seems like for what you are asking, your functions would look like this:

def stackright(self, data=None):
    if data is None: data = self.data
    for i in range(4):
        if data[i][3] == data[i][2]:
            if data[i][1] == data[i][0]:
                data[i][3] = data[i][3] *2
                self.score += data[i][3]
                data[i][2] = data[i][1] *2
                self.score += data[i][2]
                data[i][0] , data[i][1] = 0,0
            else:
                data[i][3] = data[i][3] *2
                self.score += data[i][3]
                data[i][2] = data[i][1]
                data[i][1] = data[i][0]
                data[i][0] = 0
        elif data[i][2] == data[i][1]:
                data[i][2] = data[i][2] *2
                self.score += data[i][2]
                data[i][1] = data[i][0]
                data[i][0] = 0
        elif data[i][1] == data[i][0]:
            data[i][1] = data[i][1] *2
            self.score += data[i][1]
            data[i][0] = 0
    return data
def stackleft(self, data=None):
    if data == None: data = self.data
    for i in range(4):
        if data[i][0] == data[i][1]:
            if data[i][2] == data[i][3]:
                data[i][0] = data[i][0] *2
                self.score += data[i][0]
                data[i][1] = data[i][2] *2
                self.score += data[i][1]
                data[i][3] , data[i][2] = 0,0
            else:
                data[i][0] = data[i][0]*2
                self.score += data[i][0]
                data[i][1] = data[i][2]
                data[i][2] = data[i][3]
                data[i][3] = 0
        elif data[i][1] == data[i][2]:
                data[i][1] = data[i][1] *2
                self.score += data[i][1]
                data[i][2] = data[i][3]
                data[i][3] = 0
        elif data[i][2] == data[i][3]:
            data[i][2] = data[i][2] *2
            self.score += data[i][2]
            data[i][3] = 0
    return data

And then calling data.stackright() will operate on the self data, but calling data.stackright(matrix2) will operate on matrix2 (while adding the score to data, unless you change that part above)