Using dtype object and loadtxt command to read file contents into a Numpy array

gistfile1.py

#simref.1        653     T       TT      GT      TT
#simref.1        1216    T       CC      CC      CC
#simref.1        1440    A       AA      AG      AA
#simref.1        1470    A       CC      CC      CC
#simref.1        2070    C       AA      AA      AA
#simref.1        2489    C       GG      GG      GG
import numpy as np
dt = np.dtype( [ ('chrom', 'S8'), ('pos', 'int32'), ('ref','S1'), ('father','S2'), ('mother','S2'), ('child','S2')] )
pgm_array=np.loadtxt(file,delimiter='\t',dtype=dt)