Pandas: Selecting rows for which groupby.sum() satisfies condition

Question

In pandas I have a dataframe of the form:

>>> import pandas as pd  
>>> df = pd.DataFrame({\'ID\':[51,51,51,24,24,24,31], \'x\':[0,1,0,0,1,         


        

Answer 1

df = pd.DataFrame({'ID':[51,51,51,24,24,24,31], 'x':[0,1,0,0,1,1,0]})
df.loc[df.groupby(['ID'])['x'].transform(func=sum)>=2,:]
out:
   ID  x
3  24  0
4  24  1
5  24  1