Tri des valeurs dans le dictionnaire dans Python

#instead of using python inbuilt function we can it compute directly.
#here iam sorting the values in descending order..
d = {1: 1, 7: 2, 4: 2, 3: 1, 8: 1}
s=[]
for i in d.items():
  s.append(i)
for i in range(0,len(s)):
  for j in range(i+1,len(s)):
    if s[i][1]<s[j][1]:
      s[i],s[j]=s[j],s[i]
print(dict(s))
Troubled Tuatara