Question

我的列表中有元组：

a = [((1, 6), (8, 2)), ((8, 2), (6, 3)), ((6, 3),(9,4))]

我想使用“ for”来分配列表中的所有值，例如：

P = [1,6], Q = [8,2] => perform find a straight line, then
P = [8,2], Q = [6,3] => perform find a straight line, then
P = [6,3], Q = [9,4] => perform find a straight line, then

在屏幕上输出：

PQ1 : y = b1x+c1
PQ2 : y = b2x+c2

最大值d

但是我有错误：

“浮动”对象不可迭代

在这种情况下，我不知道如何使用“”，“功能”和“类”

def function(P,Q):
   a = float(P[0]-Q[0])
   b = float(Q[1]-P[1])
   c = float((b*P[0]+a*P[1]))
   d = b/(-a)
   e = (-c)/(-a)
   if d == 0.0 and e == 0.0:
      print("False")
   elif d == 0.0:
      print("Function is y = ",e)
   elif d == 1.0 and e == 0.0:
      print("Function is y = x")
   elif d != 1.0 and e == 0.0:
      print("Function is y = ",d,"x")
   elif d == 1.0 and e > 0:
      print("Function is y = x + ",e)
   elif d == 1.0 and e < 0:
      print("Function is y = x ",e)
   elif e > 0:
      print("Function is y =",d,"x +",e)
   elif e < 0:
      print("Function is y =",d,"x",e)
if __name__ == '__main__': 
   P = [1,6]
   Q = [8,2]
   function(P,Q)

我想使用“代表”，“功能”和“类”，而不是手动将每个值分配给P和Q，因为元组可以扩展更多

非常感谢您

Answer 1

代码：

for P, Q in a:
    function(P, Q)

为什么起作用？

  a = [((1, 6), (8, 2)), ((8, 2), (6, 3)), ((6, 3),(9,4))]

如果您要使用单个变量遍历a，则每次迭代都会将list元素放入此变量中。如果您在for循环中提供2个变量，则python将尝试解压缩列表元素，如果element是可迭代的并且其元素数等于您提供的变量数量， ll将值按相同顺序放入变量。

演示代码：

a, b, c, d = (1, 2, 3, 4)  # working
print(a, b, c, d)
a, b, c, d = [1, 2, 3, 4]  # working
print(a, b, c, d)
a, b, c, d = {1, 2, 3, 4}  # working
print(a, b, c, d)
a, b, c, d = "1234"        # working
print(a, b, c, d)
a, b, c, d = range(1, 5)   # working
print(a, b, c, d)
a, b, c, d = (1, 2)        # error

从元组到输出最大值的两点的直线方程

1 个答案: