import matplotlib.pylab as plt
import csv

x = []
y = []
with open('C:/Users/dell/Desktop/D39_p5_1_10V.txt', 'r') as f:
    reader = csv.reader(f, delimiter='t')
    for row in reader:
        x.append(row[0])
        y.append(row[1])

plt.plot(x, y)
plt.xlabel('Wavelength (nm)')
plt.ylabel('Intensity (a.u)')
plt.title('D39_p5_1_10V')
plt.show()
plt.savefig('D39_p5_1_10V.png')