Or how about this:
Create the table:
>>> import pandas as pd
>>> df2 = pd.DataFrame([{"uid": 0, "mi":1}, {"uid": 0, "mi":2}, {"uid": 0, "mi":1}, {"uid": 0, "mi":1}])
Get the counts of each occurance:
>>> vc = df2.mi.value_counts()
>>> print vc
1 3
2 1
Print out those that occur more than 2 times:
>>> print vc[vc > 2].index[0]
1