将以下代码转换为python：%根据交叉概率判断是否交叉 pick=rand; while pick==0 pick=rand; end if pick>pc %随机数大于交叉概率时拒绝交叉，返回while循环 continue; end % flag=0; % while flag==0 %选中的染色体开始交叉 %选择交叉位置 pick1=rand; pick2=rand; pick3=rand; pick4=rand; while pick1*pick2*pick3*pick4==0 pick1=rand; pick2=rand; pick3=rand; pick4=rand; end %单点交叉 posx=ceil(pick1*(lenx-1)); posy=ceil(pick2*(leny-1)); %x、y交叉 ax1=x(index(1),1:posx); cx1=setdiff(x(index(2),:),ax1,'stable'); %x(index(2))中存在而ax1中不存在的值 bx2=cx1(1:lenx-posx); dx1=x(index(1),posx+1:lenx); ax2=x(index(2),1:posx); cx2=setdiff(x(index(1),:),ax2,'stable'); bx1=cx2(1:lenx-posx); dx2=x(index(2),posx+1:lenx); x(index(1),:)=[ax1,bx2]; x(index(2),:)=[ax2,bx1]; ay1=y(index(1),1:posy); by1=y(index(1),posy+1:leny); ay2=y(index(2),1:posy); by2=y(index(2),posy+1:leny); y(index(1),:)=[ay1,by2]; y(index(2),:)=[ay2,by1];

# 根据交叉概率判断是否交叉
import random

pick = random.random()
while pick == 0:
    pick = random.random()
if pick > pc:  # 随机数大于交叉概率时拒绝交叉，返回while循环
    continue

flag = 0
while flag == 0:
    # 选中的染色体开始交叉
    # 选择交叉位置
    pick1 = random.random()
    pick2 = random.random()
    pick3 = random.random()
    pick4 = random.random()
    while pick1 * pick2 * pick3 * pick4 == 0:
        pick1 = random.random()
        pick2 = random.random()
        pick3 = random.random()
        pick4 = random.random()

    # 单点交叉
    posx = int(pick1 * (lenx - 1))
    posy = int(pick2 * (leny - 1))

    # x、y交叉
    ax1 = x[index[0]][0:posx]
    cx1 = [i for i in x[index[1]] if i not in ax1]  # x[index(2))中存在而ax1中不存在的值
    bx2 = cx1[0:lenx - posx]
    dx1 = x[index[0]][posx + 1:lenx]

    ax2 = x[index[1]][0:posx]
    cx2 = [i for i in x[index[0]] if i not in ax2]
    bx1 = cx2[0:lenx - posx]
    dx2 = x[index[1]][posx + 1:lenx]

    x[index[0]] = ax1 + bx2
    x[index[1]] = ax2 + bx1

    ay1 = y[index[0]][0:posy]
    by1 = y[index[0]][posy + 1:leny]
    ay2 = y[index[1]][0:posy]
    by2 = y[index[1]][posy + 1:leny]

    y[index[0]] = ay1 + by2
    y[index[1]] = ay2 + by1