pandas

>>> import pandas as pd>>> df = pd.DataFrame([[1,1,1,1],[2,2,2,2],[3,3,3,3],[4,4,4,4]])>>> columns = ["col1","col2","col3","col4"]>>> df   0  1  2  30  1  1  1  11  2  2  2  22  3  3  3  33  4  4  4  4>>> df = pd.DataFrame([[1,1,1,1],[2,2,2,2],[3,3,3,3],[4,4,4,4]],columns=["col1","col2","col3","col4"])>>> df   col1  col2  col3  col40     1     1     1     11     2     2     2     22     3     3     3     33     4     4     4     4>>> df.mean(axis=1)0    1.01    2.02    3.03    4.0dtype: float64>>> df.drop("col3",axis=1)   col1  col2  col40     1     1     11     2     2     22     3     3     33     4     4     4>>> df.drop("1",axis=0)Traceback (most recent call last):  File "<pyshell#13>", line 1, in <module>    df.drop("1",axis=0)  File "D:\Python\lib\site-packages\pandas\core\generic.py", line 2161, in drop    new_axis = axis.drop(labels, errors=errors)  File "D:\Python\lib\site-packages\pandas\core\indexes\base.py", line 3624, in drop    labels[mask])ValueError: labels ['1'] not contained in axis>>> df.drop(1,axis=0)   col1  col2  col3  col40     1     1     1     12     3     3     3     33     4     4     4     4>>> df.index()Traceback (most recent call last):  File "<pyshell#15>", line 1, in <module>    df.index()TypeError: 'RangeIndex' object is not callable>>> df.index = range(4)>>> df.indexRangeIndex(start=0, stop=4, step=1)>>> df   col1  col2  col3  col40     1     1     1     11     2     2     2     22     3     3     3     33     4     4     4     4>>> df1 = df[['col3','col4']]>>> df1   col3  col40     1     11     2     22     3     33     4     4>>> df1.to_dict(orient='dict'){'col3': {0: 1, 1: 2, 2: 3, 3: 4}, 'col4': {0: 1, 1: 2, 2: 3, 3: 4}}>>> df1.to_dict(orient='records')[{'col3': 1, 'col4': 1}, {'col3': 2, 'col4': 2}, {'col3': 3, 'col4': 3}, {'col3': 4, 'col4': 4}]>>> df1.to_dict(orient='records')[0]{'col3': 1, 'col4': 1}>>>