python///TypeError: unsupported operand type(s) for -: 'list' and 'list' ,i write the code and i get this massege N = int(input('number of traverse='))
x = []
y = []
for r in range(N):
    x.append([float(input('enter x='))])
for l in range (N) :
    y.append([float(input('enter y='))])

N=N-1
b=int(N)
area = x[0] * (y[1] - y[b]) + x[b] * (y[0] - y[b-1])

for k in range(1, N):
    area = area + x[k] * (y[k+1] - y[k - 1])
    i=i+1
area = .5 *abs(area)**strong text**
```
The problem is x[0] etc are resulting in a 1D list. You need to extract element from 1D list.. below works (I used index 0 element)

area = x[0][0] * (y[1][0] - y[b][0]) + x[b][0] * (y[0][0] - y[b-1][0])