For I in range (17):?

Question

What is the output of this code?
I=[ ]
for i in range(17):
l.append(i * 3)
m = [x&1 for x in I]
print(sum(m))
Output: 8

Append means place something in the back of the list. Range is 0-17. So not sure if I should take everything times three?
Also, what does [x&1 for x in l] mean?
Thanks for any help anyone could provide:).

Answer 1

The indentations for the code are off, so I'm assuming

l = []
for i in range(17):
l.append(i*3)
m = [x&1 for x in l]
print(sum(m))

range(17) returns 0 to 16, so list l with contain 0*3, 1*3, 2*3... , 16*3

[x&1 for x in l] builds a new list consisting of every element in list l, after you bitwise AND them with 1.

https://www.tutorialspoint.com/JUMP_LINK__&&__python__&&__JUMP_LINK/bitwise_operators_example.htm

You can always try to print the list contents if you're not sure what the code does.

l = []
for i in range(17):
l.append(i*3)
print(l)
m = [x&1 for x in l]
print(m)
print(sum(m))

Answer 2

m = [
0&1
00000000
&
00000001
=
00000000,

3&1
00000011
&
00000001
=
00000001,

6&1
00000110
&
00000001
=
00000000,

9&1
00001001
&
00000001
=
00000001,

12&1
00001100
&
00000001
=
00000000,

15&1
...] => m=[0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0]

As a result, when x is equal to odd numbers, x&1 = 1, x&2 = 2, x&3 = 3, ...

Answer 3

Thanks Fermi and Vasiliy:).