for file in data:
sp = np.loadtxt(file, skiprows=0, delimiter=',',usecols=1)
sp = intensity_normalization(sp, norm='maxmin')
print(wn,sp)
np.savetxt("all.csv", dd, delimiter=',')
for file in data:
sp = np.loadtxt(file, skiprows=0, delimiter=',',usecols=1)
sp = intensity_normalization(sp, norm='maxmin')
print(wn,sp)
np.savetxt("all.csv", dd, delimiter=',')