python - Logical indexing with lists

Question

I have a program I'm looking through and with this section

temp = [1,2,3,4,5,6]
temp[temp!=1]=0
print temp

Which if run gives the result:

[1, 0, 3, 4, 5, 6]

I need help understanding what is going on in this code that leads to this result.

Answer 1

temp in your example is a list, which clearly is not equal to 1. Thus the expression

 temp[temp != 1] = 0

is actually

temp[True] = 0  # or, since booleans are also integers in CPython
temp[1] = 0

Convert temp to a NumPy array to get the broadcasting behaviour you need

>>> import numpy as np
>>> temp = np.array([1,2,3,4,5,6])
>>> temp[temp != 1] = 0
>>> temp 
array([1, 0, 0, 0, 0, 0])