Python: Elegant and efficient ways to mask a list

Question

Example:

from __future__ import division
import numpy as np

n = 8
\"\"\"masking lists\"\"\"
lst = range(n)
print lst

# the mask (filter)         


        

Answer 1

If you are using Numpy, you can do it easily using Numpy array without installing any other library:

>> a = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
>> msk = [ True, False, False,  True,  True,  True,  True, False, False, False]
>> a = np.array(a) # convert list to numpy array
>> result = a[msk] # mask a
>> result.tolist()
[0, 3, 4, 5, 6]