Groupby to find min date with conditions in Python
Use boolean index with loc and min:
df.loc[(df['Column_A'] == 'A') & (df['Column_B'] == 'type 1'), 'Date'].min()
I have like 3 columns in a data frame for example
Column_A has 2 categorical values like A,B 
Column_B also has 3 categorical values like Type1, Type2, Type3    
Date column has values like 2010-06-13,2010-06-10
There are about 20,000 rows so the Categorical Column A,B's values keep repeating.
So  I need the find min date where Column_A='A' and Column_B='type 1' using Python(Pandas,Numpy)