import numpy as np 
def mother_wavelet(t):
    for i in range(np.size(t)):
        if t[i] >= 0 or t[i] < 0.5:
            mat_psi = 1
        elif t[i] >= 0.5 or t[i] <= 1:
            mat_psi = -1
        else:
            mat_psi = 0
    return mat_psi

t = [0 0.066 0.133 0.2 0.266 0.333 0.4 0.466 0.533 0.6 0.666 0.733 0.8 0.866 0.933 1]

  File "D:\......\mother_wavelet.py", line 15, in mother_wavelet
    if t[i] >= 0 or t[i] < 0.5:
IndexError: invalid index to scalar variable.

import numpy as np 
def mother_wavelet(t):
    for i in range(np.size(t)):
        if t[i] >= 0 or t[i] < 0.5:
            mat_psi = 1
        elif t[i] >= 0.5 or t[i] <= 1:
            mat_psi = -1
        else:
            mat_psi = 0
    return mat_psi
t = [0, 0.066, 0.133, 0.2, 0.266, 0.333, 0.4, 0.466, 0.533, 0.6, 0.666, 0.733, 0.8, 0.866, 0.933, 1]
print mother_wavelet(t)
>>> 1