DFT

#Discrete Fourier Transform
from pylab import *
def dft(h):
    N=len(h)
    w=2*pi/N
    H=[]
    for n in xrange(N):
        s=0
        for k in xrange(N):
            s+=h[k]*exp(w*k*n*1j)
        H.append(s)
    return H

hk=[1,2,3,4]
print dft(hk)

Output Screen
[(10+0j), (-2.0000000000000004-1.9999999999999996j), (-2+9.7971743931788257e-16j), (-1.9999999999999982+2.0000000000000009j)]