问题描述
"can't multiply sequence by non-int of type 'list'".
我正在努力解决它，请有人告诉我我的任务。
import matplotlib.pyplot as plt
import random
class RandomWalk():
def __init__(self,num_points = 5000):
#Initialize attributes of a walk
self.num_points = num_points
# walk start at (0,0)
self.x_value = [0]
self.y_value = [0]
def walk(self):
while len(self.x_value) < self.num_points:
# Decide which direction to go and how far to go in that direction.
x_direction = random.choices([1,-1])
x_distance = random.choices([0,1,2,3,4])
x_step = x_direction * x_distance # here i am getting this error I'm trying to resolve but not able to fix some body help me...
y_direction = random.choices([1,-1])
y_distance = random.choices([0,4])
y_step = y_direction * y_distance
# Reject moves that go Nowhere.
if x_step == 0 and y_step == 0:
continue
# Calculate the next x and y values.
next_x = self.x_value[-1] + x_step
next_y = self.y_value[-1] + y_step
self.x_value.append(next_x)
self.y_value.append(next_y)
# Make a random walk,and plot the points.
rw = RandomWalk()
rw.walk()
plt.scatter(rw.x_value,rw.y_value,s = 15)
plt.show()
解决方法
由于x_direction和x_distance是列表，导致了错误。您必须使用random.choice而不是random.choices（最后要注意s）
x_direction = random.choice([1,-1])
x_distance = random.choice([0,1,2,3,4])
x_step = x_direction * x_distance
random.choice返回列表的1个元素，而random.choices返回一个 k 个元素的列表，其中 k 是可选参数。参见random