install

1	pip install matplotlib

basic plot

import matplotlib.pyplot as plt
'''if you want to use jupyter to show the graph, add the command below'''
%matplotlib inline

plt.figure() # generate the whole figure, and configure it
plt.subplot(xyz) # plot a graph, the figure contains x rows, y columes, and now plot the zth graph
plt.plot(x,y,...) # real plot something
plt.show() # show the graph on the screen
plt.savefig(name,...) # save the figure

element of a figure

details

to find more info, use matplotplib.pyplot API

plt.plot(x, y1, color="blue", linewidth=1.0, linestyle="-", label="bla"...) # configure the line style
plt.ylim(-2, 10)
plt.xlim(-1,6) # set the upper and lower bound of the axis
plt.xlabel("bla")
plt.ylabel("bla") # the label of x/y axis
plt.xticks([-1, -0.5, 0, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5])
plt.yticks([-2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9]) # ticks of x/y axis
plt.legend(loc ="upper left") # the legend configure of the graph, need to add label at plot call
plt.scatter([3], [0], s=50, color="#800080") # add a scatter point
plt.annotate("bla", xy=(3.3, 0),  fontsize=16,  xycoords='data')    # add a piece of annotate at xy location
plt.text(4, -0.5, "this point very important",  fontdict={'size': 12, 'color': 'green'}) # add a piece of text at (4,-0.5)
plt.suptitle("") # add title to the figure
plt.title("") # title of the axes

bar

1	plt.bar(x，height， width，，align='center'，*kwargs)

box

1	plt.boxplot()

note: the figure will plot the upper quartile $Q_3$, the lower quartile $Q_1$, the median. let $IQR=Q_3-Q_1$ be the interquartile range. Then the lower whisker (fence) is at $max(mindata, Q_1-1.5IQR)$ and the upper whisker (fence) is at $min(maxdata, Q_3+1.5IQR)$. The points below lower whisker and above the upper whisker are the so called outliers or fliers.