如何更改功能或避免错误

Question

我不知道我是否写错了“line”函数，或者在“for”之后的最后一条语句中是否还有其他内容，请帮助我。 该程序是关于斜率和这些值之间的比较，但首先我需要找到它们，但有些东西不起作用。 代码如下：

import math

N = int(input("Number of points: "))

def line(x0,y0,x1,y1):
  if(x0==x1):
    print("\nThe slope doesn't exist\n")
    return None
  if((x0-x1)!=0):
    m = (y1-y0)/(x1-x0)
    return m

for i in range(N):
  for j in range(N):
    ind = None
    for ind in range(N):
      x_ind = {}
      y_ind = {}
      x_ind[i] = float(input("Enter x_" + str(ind) + ": "))
      y_ind[j] = float(input("Enter y_" + str(ind) + ": "))
    for _ in range(math.factorial(N-1)):
      line(x_ind[i], y_ind[j], x_ind[i+1], y_ind[j+1])
      

Answer 1

TL;DR - 您在 for 循环中声明您的字典，因此每次新迭代都会重置它们。

---

我认为你正在尝试这样做 -

N = int(input("Number of points: "))

def line(x0,y0,x1,y1):
  # calculate slope for (x0,y0) and (x1,y1)
  if x0 == x1:            # it will be a vertical line, it has 'undefined' slope
    # print("The slope doesn't exist\n")
    return None           # Slope Undefined
  else:                   # this is implied, no need to put extra check --> x0-x1 != 0:
    return (y1-y0)/(x1-x0)
  pass

# declare variables
x_ind = {}
y_ind = {}
for i in range(N):
  # read inputs and update the existing variables
  x_ind[i] = float(input("Enter x_" + str(i) + ": "))
  y_ind[i] = float(input("Enter y_" + str(i) + ": "))
  print(x_ind, '\n', y_ind)

# calculate slope for every pair of points
for j in range(N):
  for k in range(j+1,N):
    m = line(x_ind[j], y_ind[j], x_ind[k], y_ind[k])
    print(f'slope of line made using points: ({x_ind[j]}, {y_ind[j]}) and ({x_ind[k]}, {y_ind[k]}) is {m}')

---

样本输入：

Number of points: 3

Enter x_0: 3
Enter y_0: 0

Enter x_1: 0
Enter y_1: 4

Enter x_2: 0
Enter y_2: 0

---

示例输出：

slope of line made using points: (3.0, 0.0) and (0.0, 4.0) is -1.3333333333333333
slope of line made using points: (3.0, 0.0) and (0.0, 0.0) is -0.0
slope of line made using points: (0.0, 4.0) and (0.0, 0.0) is None

Answer 2

尝试使用列表而不是字典来正确处理索引值：

x_ind = []
y_ind = []

由于列表是空的，您可以使用append()方法将元素推送到列表，因为我可以看到这是您打算做的。