How to plot pulse width/value data in python using matlab

I am trying to plot some pulse width (microsecond duration) and pulse value (0/1). The issue seems to be with the x axis which I did not specify as no idea how to do that. Here is the code. The attachment shows the current plot. Any help would be appreciated. Thanks!

import matplotlib.pyplot as plot
import csv

durations = []
values = []

with open("/home/pi/dsc/pulseFile.csv", "r") as csvfile:

    for row in csv.reader(csvfile, quoting=csv.QUOTE_NONE):

        durations.append(row[0])
        values.append(row[1])

dur = durations[0:200]
val = values[0:200]

print('**Display sample of data to plot**')

for x in range(10):
    print(dur[x])
    print(val[x])

print('**Plotting results**')
plot.title('My Data')
plot.xlabel('Time')
plot.ylabel('Amplitude')
plot.plot(dur, val)
plot.show()