how does string reversal work python code example

Example 1: reverse string method python

#linear

def reverse(s): 
  str = "" 
  for i in s: 
    str = i + str
  return str

#splicing
'hello world'[::-1]

#reversed & join
def reverse(string): 
    string = "".join(reversed(string)) 
    return string

Example 2: string reverse in python

str1="Hello"
#if u want to take length input from user then use the next line 
#n=int(input("enter the no of elements: ")) #this one 

#if u don't wanna ask user the length then directly use this next line
n=len(str1)

for i in range(-1,-(n+1),-1):
        print(str1[i],end='')
#prints olleh