Python for loops and comprehension for loops

Question

Can someone explain to me why would this two statements (the for loop and the comprehension ) return two different answers. I thought they were the same, just different ways of

Answer 1

you are setting the whole column (vector) in each iteration step:

Top152['HighRenew'] = 1

Try this vectorized approach instead:

Top152['HighRenew'] = (Top152['% Renewable'] >= Top152['% Renewable'].median()).astype(int)

so your function may be implemented as follows:

def answer_ten():
    return (Top15['% Renewable'] >= Top15['% Renewable'].median()).astype(int)