Can someone explain this I don't know how I got it

Question

rows = int(input())
for i in range(0, rows):
for j in range(0, i+1):
print("*", end = ' ')
print("\r")

for i in range(rows, 0, -1):
for j in range(0, i-1):
print("*", end=' ')
print("\r")

Answer 1

Tshegofatso Sekgothe

range(start, end)

Suppose rows = 5 so range will give [0, 1, 2, 3, 4]

There is nested loop and inner loop will depends on outer loop so

If rows is 5 then outer loop will work till 5 times

And inner loop will run ith times so if i = 0 then range(0, 0 + 1) = range(0, 1)
So inner loop will work 1 time

If i = 1 then inner loop will work 2 times
i = 2 then 3 times
i = 3 then 4 times

So your pattern will be

* => i = 0, j = 1
** => i = 1, j = 2
*** => i = 2, j = 3
**** => i = 3, j = 4
***** => i = 4, j = 5

end = ' ' is used to do not print with new line

range(rows, 0, -1) will give you 4, 3, 2, 1, 0

Your loop will work in reverse order and pattern will be

****
***
**
*