Matplotlib.markers module in Python

Matplotlib is an amazing visualization library in Python for 2D plots of arrays. Matplotlib is a multi-platform data visualization library built on NumPy arrays and designed to work with the broader SciPy stack.

Matplotlib.markers

The matplotlib.dates module provides functions to handle markers in Matplotlib. It is used both by the marker functionality of the plot and scatter.
Below is the table defining all possible markers in matplotlib:

Marker	Description
“.”	point
“, “	pixel
“o”	circle
“v”	triangle_down
“^”	triangle_up
“<“	triangle_left
“>”	triangle_right
“1”	tri_down
“2”	tri_up
“3”	tri_left
“4”	tri_right
“8”	octagon
“s”	square
“p”	pentagon
“P”	plus (filled)
“*”	star
“h”	hexagon1
“H”	hexagon2
“+”	plus
“x”	x
“X”	x (filled)
“D”	diamond
“d”	thin_diamond
“|”	vline
“_”	hline
0 (TICKLEFT)	tickleft
1 (TICKRIGHT)	tickright
2 (TICKUP)	tickup
3 (TICKDOWN)	tickdown
4 (CARETLEFT)	caretleft
5 (CARETRIGHT)	caretright
6 (CARETUP)	caretup
7 (CARETDOWN)	caretdown
8 (CARETLEFTBASE)	caretleft (centered at base)
9 (CARETRIGHTBASE)	caretright (centered at base)
10 (CARETUPBASE)	caretup (centered at base)
11 (CARETDOWNBASE)	caretdown (centered at base)
“None”, ” ” or “”	nothing
‘$…$’	Render the string using mathtext. E.g “$r$” for marker showing the letter r.
verts	A list of (x, y) pairs used for Path vertices. The center of the marker is located at (0, 0) and the size is normalized, such that the created path is encapsulated inside the unit cell.
path	A Path instance
(numsides, style, angle)	The marker can also be a tuple (numsides, style, angle), which will create a custom, regular symbol.  A) numsides: the number of sides B) style: the style of the regular symbol,  0: a regular polygon  1: a star-like symbol  2: an asterisk C) angle: the angle of rotation of the symbol

Note: It is important to note that the two lines of code below are equivalent, 

# line 1
plt.plot([1, 2, 3], marker = 9)

# line 2
plt.plot([1, 2, 3], marker = matplotlib.markers.CARETRIGHTBASE)

Example 1:

Python3

import numpy as np
import matplotlib.pyplot as plt
from matplotlib.lines import Line2D


# Draw 5 points for each line
each_point = np.ones(5)
style = dict(color = 'tab:green',
             linestyle = ':',
             marker = 'D',
             markersize = 15,
             markerfacecoloralt = 'tab:red')

figure, axes = plt.subplots()

# Plot all filling styles.
for y, fill_style in enumerate(Line2D.fillStyles):

    axes.text(-0.5, y,
              repr(fill_style),
              horizontalalignment = 'center',
              verticalalignment = 'center')

    axes.plot(y * each_point, fillstyle = fill_style,
              **style)

axes.set_axis_off()
axes.set_title('filling style')

plt.show()

Output:

Example 2:

Python3

import numpy as np
import matplotlib.pyplot as plt
from matplotlib.lines import Line2D


# Drawing 3 points for each line
plotted_points = np.ones(4)
txt_style = dict(horizontalalignment = 'right',
                 verticalalignment = 'center',
                 fontsize = 12,
                 fontdict = {'family': 'monospace'})

style = dict(linestyle = ':',
             color ='0.5',
             markersize = 10,
             mfc ="C0",
             mec ="C0")


# helper function for axes formatting
def format_ax(ax):

    ax.margins(0.2)
    ax.set_axis_off()
    ax.invert_yaxis()


# helper function for splitting list
def split(a_list):

    i_half = len(a_list) // 2
    return (a_list[:i_half], a_list[i_half:])

figure, axes = plt.subplots(ncols = 2)

for ax, markers in zip(axes, split(Line2D.filled_markers)):

    for y, marker in enumerate(markers):

        ax.text(-0.5, y, repr(marker), **txt_style)
        ax.plot(y * plotted_points, marker = marker,
                **style)

    format_ax(ax)

figure.suptitle('filled markers', fontsize = 14)

plt.show()

Output: