Basics

import matplotlib
import matplotlib.pyplot as plt
import matplotlib.ticker as mticker
import matplotlib.dates as mdates
import numpy as np
from numpy import loadtxt
from matplotlib import style
style.use("ggplot")



def graphRawFX():
    date,bid,ask = np.loadtxt('GBPUSD1d.txt', unpack=True,
                              delimiter=',',
                              converters={0:mdates.strpdate2num('%Y%m%d%H%M%S')})

    fig=plt.figure(figsize=(10,7))

    ax1 = plt.subplot2grid((40,40), (0,0), rowspan=40, colspan=40)
    ax1.plot(date,bid)
    ax1.plot(date,ask)
    ax1.xaxis.set_major_formatter(mdates.DateFormatter('%Y-%m-%d %H:%M:%S'))
    #####
    plt.grid(True)
    for label in ax1.xaxis.get_ticklabels():
            label.set_rotation(45)
    plt.gca().get_yaxis().get_major_formatter().set_useOffset(False)

    #######
    ax1_2 = ax1.twinx()
    
    #ax1_2.plot(date, (ask-bid))
    
    ax1_2.fill_between(date, 0, (ask-bid), facecolor='g',alpha=.3)
    
    #ax1_2.set_ylim(0, 3*ask.max())
    #######
    
    plt.subplots_adjust(bottom=.23)
    #plt.grid(True)
    
    plt.show()
    


graphRawFX()
		

The next tutorial: Percent Change