Hi,
  I thought that I can easily create a list of, say 3, nested lists:

$ python
Python 2.7.3 (default, May 17 2012, 21:10:41) 
[GCC 4.5.3] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> 3 * [[]]
[[], [], []]
>>> a=3 * [[]]
>>> a[0]
[]
>>> a[1].append('sdds')
>>> a
[['sdds'], ['sdds'], ['sdds']]
>>> a[0].append('xxx')
>>> a
[['sdds', 'xxx'], ['sdds', 'xxx'], ['sdds', 'xxx']]


The below works as expected.

>>> a=[[], [], []]
>>> a
[[], [], []]
>>> a[0]
[]
>>> a[1]
[]
>>> a[1].append('sdds')
>>> a[0].append('xxx')
>>> a
[['xxx'], ['sdds'], []]
>>>


Of course, I want to do like:

a = len(b) * [] # to get a list of individual hashes
c = len(b) * [0] # to get a list of indvidual counters

The * operator does not create copies, it duplicates references to existing objects.
Please read: http://docs.python.org/faq/programming.html#how-do-i-create-a-multidimensional-list

For the sake of internet archives, the following could be included in the FAQ you referred to:

http://www.scipy.org/Cookbook/BuildingArrays

>>> import numpy as np
>>> a=np.array(5*[False],bool)
>>> a
array([False, False, False, False, False], dtype=bool)
>>> a[4]=1
>>> a
array([False, False, False, False,  True], dtype=bool)
>>>

But thanks for the link, it helped me at that time.

But that's about numpy, which is not part of core Python, and so doesn't belong in a Python FAQ.  But perhaps your posting it here will help someone doing an internet search...