Python Array Slicing

Question

I have the following code that executes without any problems:

my_vector = np.array([-17, -4, 0, 2, 21, 37, 105])
zero_mod_7_mask = (my_vector % 7)==0
sub_array = my_vector[zero_mod_7_mask]
sub_array[sub_array > 0]

OUT:

array([ 21, 105])

In the last line I am using '>' in the square brackets..

Now if I create a sinple array as below, it will give me an error while using '>':

a = [1,2,3,4,5,6,35,67,89]
a[a > 0]

OUT:

TypeError Traceback (most recent call last)
<ipython-input-13-f6fbf6d9ee7c> in <module>()
----> 1 a[a > 0]

TypeError: '>' not supported between instances of 'list' and 'int'

Can anyone explain why it ran in the first eg and it didnt in the 2nd?'

Thanks

Answer 1

in first cod you use NumPy - "np.array". in sec it's clear python.
Need used -
filter(lambda x: x > 0, a)

Answer 2

Damn, I might have gone crazy learning Python, dafaq m doing, I now realize it's a list. Thanks man.