Pandas dataframe slicing/selecting by comparing two column values

Question

Input Dataframe

data = {
'G_ID': ['s1','s2','s3','s4','s5','s6','s7','s8','s9'],
'id' : [753,753,753,700,700,700,581,800,800,],
's_id': [ 753,751,752,700,700,700,581,800,800]
}

df = pd.DataFrame.from_dict(data)
print (df)
  G_ID   id  s_id
0   s1  753   753
1   s2  753   751
2   s3  753   752
3   s4  700   700
4   s5  700   700
5   s6  700   700
6   s7  581   581
7   s8  800   800
8   s9  800   800

Expected output

   G_ID   id  s_id  diff
   s2  753   751    Y
   s3  753   752    Y

Trying to compare the two column values id and S_id in a data frame if the values are different, get me the subset of the data frame.