Read csv.

In [2]:
pd.read_csv('sample_file.csv')
Out[2]:
a b c
0 4 7 10
1 5 8 11
2 6 9 12

Read csv file and set index.

In [3]:
pd.read_csv('sample_file_with_index.csv', index_col=0)
pd.read_csv('sample_file_with_index.csv', index_col='i')
Out[3]:
a b c
i
1 4 7 10
2 5 8 11
3 6 9 12