Text properties and layout

The matplotlib.text.Text instances have a variety of properties which can be configured via keyword arguments to the text commands (e.g., title(), xlabel() and text()).

Property	Value Type
alpha	float
backgroundcolor	any matplotlib color
bbox	Rectangle prop dict plus key 'pad' which is a pad in points
clip_box	a matplotlib.transform.Bbox instance
clip_on	[True | False]
clip_path	a Path instance and a Transform instance, a Patch
color	any matplotlib color
family	[ 'serif' | 'sans-serif' | 'cursive' | 'fantasy' | 'monospace' ]
fontproperties	a FontProperties instance
horizontalalignment or ha	[ 'center' | 'right' | 'left' ]
label	any string
linespacing	float
multialignment	['left' | 'right' | 'center' ]
name or fontname	string e.g., ['Sans' | 'Courier' | 'Helvetica' ...]
picker	[None|float|boolean|callable]
position	(x, y)
rotation	[ angle in degrees | 'vertical' | 'horizontal' ]
size or fontsize	[ size in points | relative size, e.g., 'smaller', 'x-large' ]
style or fontstyle	[ 'normal' | 'italic' | 'oblique' ]
text	string or anything printable with ‘%s’ conversion
transform	a Transform instance
variant	[ 'normal' | 'small-caps' ]
verticalalignment or va	[ 'center' | 'top' | 'bottom' | 'baseline' ]
visible	[True | False]
weight or fontweight	[ 'normal' | 'bold' | 'heavy' | 'light' | 'ultrabold' | 'ultralight']
x	float
y	float
zorder	any number

You can lay out text with the alignment arguments horizontalalignment, verticalalignment, and multialignment. horizontalalignment controls whether the x positional argument for the text indicates the left, center or right side of the text bounding box. verticalalignment controls whether the y positional argument for the text indicates the bottom, center or top side of the text bounding box. multialignment, for newline separated strings only, controls whether the different lines are left, center or right justified. Here is an example which uses the text() command to show the various alignment possibilities. The use of transform=ax.transAxes throughout the code indicates that the coordinates are given relative to the axes bounding box, with 0,0 being the lower left of the axes and 1,1 the upper right.

import matplotlib.pyplot as plt
import matplotlib.patches as patches

# build a rectangle in axes coords
left, width = .25, .5
bottom, height = .25, .5
right = left + width
top = bottom + height

fig = plt.figure()
ax = fig.add_axes([0,0,1,1])

# axes coordinates are 0,0 is bottom left and 1,1 is upper right
p = patches.Rectangle(
    (left, bottom), width, height,
    fill=False, transform=ax.transAxes, clip_on=False
    )

ax.add_patch(p)

ax.text(left, bottom, 'left top',
        horizontalalignment='left',
        verticalalignment='top',
        transform=ax.transAxes)

ax.text(left, bottom, 'left bottom',
        horizontalalignment='left',
        verticalalignment='bottom',
        transform=ax.transAxes)

ax.text(right, top, 'right bottom',
        horizontalalignment='right',
        verticalalignment='bottom',
        transform=ax.transAxes)

ax.text(right, top, 'right top',
        horizontalalignment='right',
        verticalalignment='top',
        transform=ax.transAxes)

ax.text(right, bottom, 'center top',
        horizontalalignment='center',
        verticalalignment='top',
        transform=ax.transAxes)

ax.text(left, 0.5*(bottom+top), 'right center',
        horizontalalignment='right',
        verticalalignment='center',
        rotation='vertical',
        transform=ax.transAxes)

ax.text(left, 0.5*(bottom+top), 'left center',
        horizontalalignment='left',
        verticalalignment='center',
        rotation='vertical',
        transform=ax.transAxes)

ax.text(0.5*(left+right), 0.5*(bottom+top), 'middle',
        horizontalalignment='center',
        verticalalignment='center',
        fontsize=20, color='red',
        transform=ax.transAxes)

ax.text(right, 0.5*(bottom+top), 'centered',
        horizontalalignment='center',
        verticalalignment='center',
        rotation='vertical',
        transform=ax.transAxes)

ax.text(left, top, 'rotated\nwith newlines',
        horizontalalignment='center',
        verticalalignment='center',
        rotation=45,
        transform=ax.transAxes)

ax.set_axis_off()
plt.show()

(Source code, png, pdf)

Default Font

The base default font is controlled by a set of rcParams:

rcParam	usage
'font.family'	List of either names of font or {'cursive', 'fantasy', 'monospace', 'sans', 'sans serif', 'sans-serif', 'serif'}.
'font.style'	The default style, ex 'normal', 'italic'.
'font.variant'	Default variant, ex 'normal', 'small-caps' (untested)
'font.stretch'	Default stretch, ex 'normal', 'condensed' (incomplete)
'font.weight'	Default weight. Either string or integer
'font.size'	Default font size in points. Relative font sizes ('large', 'x-small') are computed against this size.

The mapping between the family aliases ({'cursive', 'fantasy', 'monospace', 'sans', 'sans serif', 'sans-serif', 'serif'}) and actual font names is controlled by the following rcParams:

family alias	rcParam with mappings
'serif'	'font.serif'
'monospace'	'font.monospace'
'fantasy'	'font.fantasy'
'cursive'	'font.cursive'
{'sans', 'sans serif', 'sans-serif'}	'font.sans-serif'

which are lists of font names.

Text with non-latin glyphs

As of v2.0 the default font contains glyphs for many western alphabets, but still does not cover all of the glyphs that may be required by mpl users. For example, DejaVu has no coverage of Chinese, Korean, or Japanese.

To set the default font to be one that supports the code points you need, prepend the font name to 'font.family' or the desired alias lists

matplotlib.rcParams['font.sans-serif'] = ['Source Han Sans TW', 'sans-serif']

or set it in your .matplotlibrc file:

font.sans-serif: Source Han Sans TW, Ariel, sans-serif

To control the font used on per-artist basis use the 'name', 'fontname' or 'fontproperties' kwargs documented above.

On linux, fc-list can be a useful tool to discover the font name; for example

$ fc-list :lang=zh family
Source Han Sans TW,思源黑體 TW,思源黑體 TW ExtraLight,Source Han Sans TW ExtraLight
Source Han Sans TW,思源黑體 TW,思源黑體 TW Regular,Source Han Sans TW Regular
Droid Sans Fallback
Source Han Sans TW,思源黑體 TW,思源黑體 TW Bold,Source Han Sans TW Bold
Source Han Sans TW,思源黑體 TW,思源黑體 TW Medium,Source Han Sans TW Medium
Source Han Sans TW,思源黑體 TW,思源黑體 TW Normal,Source Han Sans TW Normal
Fixed
Source Han Sans TW,思源黑體 TW,思源黑體 TW Heavy,Source Han Sans TW Heavy
Source Han Sans TW,思源黑體 TW,思源黑體 TW Light,Source Han Sans TW Light

lists all of the fonts that support Chinese.