python pandas dataframe 操作记录

从数据看select出数据后如何转换为dataframe

df = DataFrame(cur.fetchall())

如何更改列名，选取列，进行groupby操作

df.columns = ['member_id', 'poi', 'num']    
df = df[['member_id','num']]
grouped = df.groupby('member_id')
df = grouped.aggregate(lambda x: sorted(list(x),reverse=True))
df = df.reset_index()

如何对dataframe进行遍历

for index, row in df.iterrows():
    print row['c1'], row['c2']