Flexitext is a Python library that makes it easier to draw text with multiple styles in Matplotlib

Last update: Dec 28, 2022

Overview

Introduction

Flexitext is a Python library that makes it easier to draw text with multiple styles in Matplotlib. This library is inspired and influenced by the R package ggtext.

Installation

Flexitext requires a working Python interpreter (3.7+). This library can be installed using pip:

pip install flexitext

Alternatively, you can install the development version from GitHub:

pip install git+https://github.com/tomicapretto/flexitext.git

Flexitext only requires Matplotlib version 3.4 or higher.

Overview

Albeit being inspired on ggtext, Flexitext does not use HTML, CSS, or Markdown to specify text styles. On the contrary, it implements a tag-based styling that looks similar to HTML tags, but is not exactly like HTML. These formatted strings consist of three components:

An opening tag that defines the styles to apply.
The text to be styled.
A closing tag, indicating the extent to which the styles in the opening tag apply.

Let's see an example:

This is blue text and this is regular text" ">
"
    
     This is blue text and this is regular text"
    

is the opening tag. Styles are key-value pairs separated by :. Multiple styles are separated by commas.
This is blue text is the text block. This text is going to be drawn using a font size of 16 and blue color.
is the closing tag. Only the text within the opening and the closing tags is formatted.

And finally we have and this is regular text. This is going to be drawn using the default style because it is not contained within any formatting tags.

Examples

The easiest way to use flexitext is through the flexitext function.

import matplotlib as mpl
import matplotlib.pyplot as plt

from flexitext import flexitext

mpl.rcParams['figure.facecolor'] = 'w'

fig, ax = plt.subplots(figsize=(9, 6))

text = "Normal text"
ax.text(0.5, 0.7, text, size=24, ha="center")

text = "
   
    Bold text"
   
flexitext(0.5, 0.6, text, ha="center")

text = "
   
    Italic text"
   
flexitext(0.5, 0.5, text, ha="center")

text = "
   
    Bold and 
    
     italic too!"
    
   
flexitext(0.5, 0.4, text, ha="center");

Styles can be nested

It is much

easier

now" flexitext(0.5, 0.6, text, ha="center"); ">
fig, ax = plt.subplots(figsize=(9, 6))

text = "
      
       It is much 
       
        easier 
        
         now"
        
flexitext(0.5, 0.6, text, ha="center");

A more convoluted example:

You can write using\n" "

multiple formats,\nand linebreaks\n\n" "

also

bold text\n\n" "

and why not

italics too" ) fig, ax = plt.subplots(figsize=(9, 6)) flexitext(0.5, 0.5, text, ha="center", ma="center"); ">
text = (
    "
         
          You can write using
          \n"
         
    "
         
          multiple formats,
          \nand linebreaks
          \n
          \n"
         
    "
         
          also 
          
           bold text
           \n
           \n"
          
         
    "
         
          and why not 
          
           italics too"
          
         
)

fig, ax = plt.subplots(figsize=(9, 6))
flexitext(0.5, 0.5, text, ha="center", ma="center");

Use the figure fraction coordinates to write a formatted title.

A

great chart showing\n" "

the values for the " "

blues and the

reds" ) flexitext(0.025, 0.8, text, va="bottom", xycoords="figure fraction"); ">
fig, ax = plt.subplots(figsize=(9, 6))
fig.subplots_adjust(top=0.8, left=0.025)

x = [1, 2, 3]
y_blue = [2, 2.7, 4.5]
y_red = [1, 3, 2.5]

ax.scatter(x, y_blue, color="royalblue", s=120)
ax.scatter(x, y_red, color="crimson", s=120)

# Add flexitext
text = (
    "
        
          A 
          
           great chart showing
           \n"
          
    "
        
         the values for the "
        
    "
        
         blues and the 
         
          reds"
         
)
flexitext(0.025, 0.8, text, va="bottom", xycoords="figure fraction");

Notes

Flexitext only supports the following styles

alpha
backgroundcolor
color
family
name
size
style
weight

See Matplotlib's documentation for more information about their meaning and available values.

Flexitext logo is created with Flexitext and Matplotlib (see here).

Related work

highlight_text: Flexitext and highlight_text have similar goals. This library, highlight_text, allows you to customize more aspects of the highlighted text, such as the bounding box of the text or the border of the text with path effects. On the other hand, it requires you to pass a styles as a separated list of dictionaries instead of within the text.

Comments

Added Framework::Matplotlib to setup.cfg

Was having trouble finding this package, couldn't remember the name. Figure this would have helped me and make it slightly more discoverable. Also, please consider adding this package to https://matplotlib.org/mpl-third-party/

opened by story645 6
About flexitext parameter "ha" and "va"
Hello author, the ha and va parameters in the flexitext library do not seem to be consistent with those in ax.text. Set ha='center' in ax.text, the text of different lines will be aligned in the center, but this parameter seems to be invalid in flexitext (The alignment result is not quite consistent with the text). Setting ha='center' in flexitext is still left-aligned? The following is my code:

`

fig.subplots_adjust(top=0.8, left=0.025) x = [1, 2, 3] y_blue = [2, 2.7, 4.5] y_red = [1, 3, 2.5] ax.scatter(x, y_blue, color="royalblue", s=120) ax.scatter(x, y_red, color="crimson", s=120) # Add flexitext text = ( "<name:Montserrat><size:24>A <weight:bold>great chart</> showing</>\n" "<size:18>the values for the " "<color:royalblue, weight:bold>blues</> and the <color:crimson, weight:bold>reds</></></>" ) flexitext(0.5, 0.5, text, va="center", ha='center', ax=ax); #xycoords="figure fraction" ax.text(0.5, 0.2, text, va="center", ha='center',transform=ax.transAxes) plt.show()

`

Is there a parameter in flexitext that can horizontally align the text of different lines in the center (even if the text size is inconsistent)?

Thank you.
opened by JiWenzheng 4
plt.subplots?

Hi, I want to use Flexitext to draw the text of subplots, but I find that parameter transform = axes. TransAxes is not supported. Is it possible to specify coordinate system in the future?

opened by JiWenzheng 2
Several improvements and fixes
Modify dev requirements and sort them alphabetically.

Add pyproject.toml where we set the length of the black formatter.

Flexitext now parses floats like 2. as 2.0. Previously it tried to parse two different numbers, resulting in an error.

Increase coverage to 100%.

Added changelog.
opened by tomicapretto 1
Incompatibility with `constrained` layout?
I think I found a bug when using Matplotlib's constrained layout and flexitext. In this case, flexitext makes the layout very inconsistent if the window is resized, and different from what is expected. Here's some example code:

import matplotlib.pyplot as plt from flexitext import flexitext fig, ax = plt.subplots(1, 2, figsize=(12, 6), layout="constrained") text1 = "<size:42, name:Carlito>Some<color:#11557c, weight:bold> text</></>" text2 = "<size:36, name:Lato, color:royalblue><weight:bold>Here</> too</>" flexitext(0.5, 0.5, text1, ha="center", ax=ax[0]) flexitext(0.5, 0.5, text2, ha="center", ax=ax[1]) fig.set_facecolor("w") # fig.savefig("example.png", dpi=300) plt.show()

Here is a screenshot of the result:

After maximizing the window, and going back to its original size, the layout has changed:

Maximizing again, and going back to the original size:

Note that uncommenting fig.savefig("example.png", dpi=300) triggers a canvas draw and improves the layout for the given window size, but it doesn't seem to be what the layout would be without the flexitext.

Expected layout:

Layout after a canvas draw:

What do you think?
opened by guillaumedavidphd 7

Releases(v0.2.0)

v0.2.0(Mar 6, 2022)
This release includes two relevant fixes/improvements:

Add mva argument to flexitext() which controls the vertical alignment of individual texts within the outer text box.

Improve backgroundcolor behavior. The backgroundcolor of one piece of text does not overlap other pieces of text by default now.

Source code(tar.gz)
Source code(zip)
v0.1.0(Sep 21, 2021)

First release with basic functionality tested and working. We also have a static webpage, which is nice :D
Source code(tar.gz)
Source code(zip)