Filter out groups with a length equal to one
group-by, pandas, python
Solution
As of pandas 0.12 you can do:
>>> grouped.filter(lambda x: len(x) > 1)
A B
0 foo 0
2 foo 2
3 foo 3
Problem
I am creating a `groupby` object from a Pandas `DataFrame` and want to select out all the groups with > 1 size. Example: ``` A B 0 foo 0 1 bar 1 2 foo 2 3 foo 3 ``` The following doesn't seem to work: ``` grouped = df.groupby('A') grouped[grouped.size > 1] ``` Expected Result: ``` A foo 0 2 3 ```