我正在制作一个程序来寻找最近的房子和房子列表的过程。 这 3 个函数用于查找类(class),当我去打印结果时,最后给出了错误:
File "C:/Users/ASUS/.spyder-py3/tp_1.py", line 88, in percurso
Casas.remove(pos_i)
ValueError: list.remove(x): x not in list
def distancia_casas(P1, P2):
"returns distance between points"
delta_x = P2[0] - P1[0]
delta_y = P2[1] - P1[1]
distance = ((delta_x ** 2) + (delta_y ** 2)) ** 0.5
return distance
def casa_mais_proxima(P, Casas):
pos_inicial = Casas[0]
pos_mini = (len(Casas), len(Casas))
dist_mini = distancia_casas(P, pos_mini)
for c in Casas:
dist = distancia_casas(P, c)
if dist < dist_mini:
pos_mini = c
dist_mini = dist
elif dist == dist_mini and pos_inicial[0] > c[0]:
pos_mini = pos_inicial
elif dist == dist_mini and pos_inicial[0] < c[0]:
pos_mini = c
elif dist == dist_mini and pos_inicial[0] == c[0] and pos_inicial[1] > c[1]:
pos_mini = pos_inicial
elif dist == dist_mini and pos_inicial[0] == c[0] and pos_inicial[1] < c[1]:
pos_mini = c
elif dist > dist_mini:
pos_mini = pos_mini
else:
pos_mini = c
return pos_mini
def percurso(Inicial, Casas):
pos_i = Inicial
course = [pos_i,]
n = len(Casas) - 1
for c in range(n):
print(pos_i, Casas)
pos_i = casa_mais_proxima(pos_i, Casas)
Casas.remove(pos_i)
course.append(pos_i)
if (len(Casas) - 1) != 0:
course.append(Casas[0])
return course
print("percurso", percurso((3,2),[(0,1),(1,0),(1,2),(2,3)]))
谁能帮帮我? 我已经为此苦苦挣扎了 3 天,却一无所获
最佳答案
您不应该在遍历列表时从列表中删除项目。如错误消息所述,您正在尝试删除不存在的元素。因此:
您可以使用列表理解来创建一个仅包含您要删除的元素的新列表:
no_casas = [] for c in range(n): print(pos_i, Casas) pos_i = casa_mais_proxima(pos_i, Casas) no_casas.append(pos_i) course.append(pos_i) for item in no_casas: Casas.remove(item)
但是,这种方法也会导致相同的异常,因为 casa_mais_proxima
可以多次返回 Casa
中的相同元素(这是该函数的预期行为吗? )
因此:
您可以使用
Try/Except ValueError
:try: Casas.remove(pos_i) course.append(pos_i) except ValueError: print(str(pos_i) + " not in Casas")
输出:
(3, 2) [(0, 1), (1, 0), (1, 2), (2, 3)]
(2, 3) [(0, 1), (1, 0), (1, 2)]
(3, 3) not in Casas
(3, 3) [(0, 1), (1, 0), (1, 2)]
(3, 3) not in Casas
percurso [(3, 2), (2, 3), (2, 3), (3, 3), (3, 3), (0, 1)]
关于python - 函数给出错误 ValueError : list. remove(x): x not in list,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/61411914/