Помогите перевести с Pascal на Python
var s,s1:string;
i:integer;
begin
readln(s);
s1:=s;
for i:=1 to length(s1) do begin
if s1[i]='а' then s1[i]:='б' else
if s1[i]='А' then s1[i]:='Б' else
if s1[i]='б' then s1[i]:='а' else
if s1[i]='Б' then s1[i]:='А';
end;
writeln(s1);end.

Весьма признателен!

s=input()s1=""for i in range(0,len(s)):    if s[i]=="а":        s1=s1+"б"    elif s[i]=="А":        s1=s1+"Б"    elif s[i]=="б":        s1=s1+"а"    elif s[i]=="Б":        s1=s1+"А"    else:        s1=s1+s[i]print(s1)