convert uppercase to lowercase and vice versa in python

1s=input()
2new_str=""
3for i in range (len(s)):
4    if s[i].isupper():
5        new_str+=s[i].lower()
6    elif s[i].islower():
7        new_str+=s[i].upper()
8    else:
9        new_str+=s[i]
10print(new_str)
11        
12        

1def swap_string():
2	s=input()
3	swapped_string=""
4	swapped_string+=s.swapcase()
5    return swapped_string

1#Converting a given string's lower to upper case and Vise-versa
2c = input()
3i = 0
4j = [] #Declaring empty List
5for i in range(len(c)): #For Acessing elements in string. 
6    if c[i]==c[i].lower(): #For finding the Lower-case or Upper-case elements
7     j.append(c[i].upper()) #Adding the new chhanged Upper-case element to j
8    else :
9        j.append(c[i].lower()) #Adding the new changed Lower-case elements to j
10f = ''.join([str(elem) for elem in j])  #converting list to String
11print(f)
12#sample input : Ashish
13#sample output : aSHISH