TypeError: bad operand type for unary -: 'list' python

Question

I Keep getting this error, It's so simple and error is about (-x) in function but I don't know how I can fix it. Please help me.

This is my code:

import numpy as np
x = list(np.arange(0, 1, 0.1))
print (x)
def f(x):
    f = np.exp(-x)
    return f

y =f(x)

print (y)

Answer 1

Broadcasting isn't supported for vanilla Python lists. You should use list() after the operation involving broadcasting, like so:

import numpy as np
x = np.arange(0, 1, 0.1)
print(x)
def f(x):
    f = np.exp(-x)
    return f

y = list(f(x))
print(y)

Answer 2

First of all, please use different names

import numpy as np
x = list(np.arange(0, 1, 0.1))
print (x)
def func(param):
    retval = np.exp(-param)
    return retval

y = func(x)

print (y)

for start.

Then, you make a list from the np.arange, python lists don't support the unary operation - (minus) as you are using in the function (i.e. f = np.exp(-x))

numpy arrays on the other hand do support it. what you can do is not convert it to python list, or only convert it to a python list later in the process (after using the minus)