Python for loop

Question

s = ""

for i in range(3):
s = s + str(i)

print (s)

I was fiddling around and found that this printed 012 but i dont completely understand why, could someone please explain it?

Answer 1

This will run the loop from 0 to 2. Range, by default, starts running from 0 until n-1. So, you are starting loop from 0 to 2, and hence appending each generated digit to s.
In first run, s = ''+'0'
In second, s ='0'+'1'
In third, s = '01'+'2'
At the end, s = '012'