Something like this:
In [27]: df
Out[27]:
ID A B C
0 p 1 3 2
1 q 4 3 2
2 r 4 0 9
In [30]: df.set_index('ID',inplace=True)
In [31]: df
Out[31]:
A B C
ID
p 1 3 2
q 4 3 2
r 4 0 9
In [33]: df.to_dict()['B']
Out[33]: {'p': 3, 'q': 3, 'r': 0}