Python矩阵参数传递变异

Question

有人能帮帮我吗！ 我找不到错误的原因。如果我运行它一次，它工作正常，但是当我用相同的参数再次调用相同的方法时，它会保留列表的最后一个会话，而我从未保存它。我试着使用一个临时变量，但在我运行一次之后，它也被修改了( 此算法是：

def searchin(position, mattwo):
    listpos = -1
    indexone = -1
    # - - - - - -
    for i in mattwo:
        listpos += 1
        for o in i:
            if o == position:
                indexone = i.index(o)
                return listpos, indexone

def repos(reposition, listsone):
    cero, replacement = searchin('0',listsone),searchin(reposition,listsone)
    modded = listsone
    modded[replacement[0]][replacement[1]],modded[cero[0]][cero[1]] = '0', reposition

mat = [['5','4','1'],
       ['0','6','8'],
       ['7','3','2']]

repos('5',mat)
repos('7',mat)

方法serachin（）返回我们要查找的元素在矩阵3x3中的位置。工作正常吗？没有错误

repos（）方法就是问题所在。在我运行它之后，矩阵mat会随着上次运行的结果发生变化，但我从未保存它

Answer 1

这就是你想做的吗

from copy import deepcopy

def findpos(element, matrix):
    ii = -1
    jj = -1
    for i in matrix:
        ii += 1
        for o in i:
            if o == element:
                jj = i.index(o)
                return ii, jj

def switchmatrixelements(el1,el2, mat):
    pos1 = findpos(el1,mat)
    pos2 =  findpos(el2,mat)
    modded =  deepcopy(mat)
    modded[pos2[0]][pos2[1]] = el1
    modded[pos1[0]][pos1[1]] = el2
    return modded

mat = [['5','4','1'],
       ['0','6','8'],
       ['7','3','2']]

print mat
print switchmatrixelements('0','5',mat)
print switchmatrixelements('0','7',mat) 

输出：

   [['5', '4', '1'], ['0', '6', '8'], ['7', '3', '2']]
   [['0', '4', '1'], ['5', '6', '8'], ['7', '3', '2']]
   [['5', '4', '1'], ['7', '6', '8'], ['0', '3', '2']]

Answer 2

您需要在repos中执行listone的深度复制

将from copy import deepcopy添加到文件顶部，然后将modded = listsone更改为modded = deepcopy(listsone)。在repos函数的末尾，返回modded。调用repos时，将返回值赋给变量。例如，将repos('5',mat)更改为some_variable = repos('5',mat)