df = pd.DataFrame({'key1':list('aabba'), 'key2': ['one','two','one','two','one'], 'data1': ['1','3','5','7','9'], 'data2': ['2','4','6','8','10']})
print df
out:
data1 data2 key1 key2
0 1 2 a one
1 3 4 a two
2 5 6 b one
3 7 8 b two
4 9 10 a one
grouped = df.groupby('key1')
print grouped
out:
<pandas.core.groupby.groupby.DataFrameGroupBy object at 0x7fe4511e04d0>
grouped_1 = grouped.get_group('a').reset_index()#get_group取group,reset_index取預設的index
print grouped_1
index data1 data2 key1 key2
0 0 1 2 a one
1 1 3 4 a two
2 4 9 10 a one
get_group是DataFrameGroupBy的方法,不是DataFrame的方法