cannot change font to Helvetica in Matplotlib in Python on Mac OS X 10.6

Question

I am trying to change the matplotlib font to helvetica, which I'd like to use in a PDF plot. I try the following:

import matplotlib
matplotlib.use('PDF')
import matplotlib.pylab as plt
from matplotlib import rc
plt.rcParams['ps.useafm'] = True
rc('font',**{'family':'sans-serif','sans-serif':['Helvetica']})
plt.rcParams['pdf.fonttype'] = 42

This does not work -- when I run my code with --verbose-debug, I get the error:

backend WXAgg version 2.8.10.1
/Library/Frameworks/Python.framework/Versions/6.2/lib/python2.6/site-packages/matplotlib/__init__.py:833: UserWarning:  This call to matplotlib.use() has no effect
because the the backend has already been chosen;
matplotlib.use() must be called *before* pylab, matplotlib.pyplot,
or matplotlib.backends is imported for the first time.
findfont: Could not match :family=sans-serif:style=normal:variant=normal:weight=normal:stretch=normal:size=medium. Returning /Library/Frameworks/Python.framework/Versions/6.2/lib/python2.6/site-packages/matplotlib/mpl-data/fonts/ttf/Vera.ttf
Assigning font /F1 = /Library/Frameworks/Python.framework/Versions/6.2/lib/python2.6/site-packages/matplotlib/mpl-data/fonts/ttf/Vera.ttf
Embedding font /Library/Frameworks/Python.framework/Versions/6.2/lib/python2.6/site-packages/matplotlib/mpl-data/fonts/ttf/Vera.ttf
Writing TrueType font

So apparently it cannot find Helvetica. I am not sure why. I have Helvetica in the afm directory of mpl-data, and when matplotlib initiates it reads it and outputs:

createFontDict: /Library/Frameworks/Python.framework/Versions/6.2/lib/python2.6/site-packages/matplotlib/mpl-data/fonts/afm/Helvetica.afm

Do I need a special .ttf Helvetica font in addition? If so, how can I get it? I know I have Helvetica on my system since I see it in Illustrator and many other programs.

I am using Enthought Python distribution as follows:

$ python
Enthought Python Distribution -- http://www.enthought.com
Version: 6.2-2 (32-bit)

Python 2.6.5 |EPD 6.2-2 (32-bit)| (r265:79063, May 28 2010, 15:13:03) 
[GCC 4.0.1 (Apple Inc. build 5488)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import matplotlib
>>> matplotlib.__version__
'0.99.3'

Any ideas how this can be fixed?

thanks.

Answer 1

Step-by-step solution for OS X 10.11 El Capitan and Python 3 (based on this post ).

1. Install fondu: brew install fondu

2. Find out matplotlib location:

    python3 -c "import matplotlib ; print(matplotlib.matplotlib_fname())"

   For me it's /usr/local/lib/python3.5/site-packages/matplotlib/mpl-data/matplotlibrc

3. Make a copy of Helvetica:

    mkdir ~/Desktop/font_copies cp /System/Library/Fonts/Helvetica.dfont ~/Desktop/font_copies

4. Convert the Helvetica copy we've made from dfont to ttf :

    cd /usr/local/lib/python3.5/site-packages/matplotlib/mpl-data/fonts/ttf/ fondu -show ~/Desktop/font_copies/Helvetica.dfont

5. Remove font cache: rm ~/.matplotlib/fontList.py3k.cache

Done! Now you can use Helvetica:

import matplotlib.pyplot as plt
plt.rc('font', family='Helvetica')

Answer 2

解决方案是使用fondu 将Mac OS X 中的.dfont Helvetica 字体转换为.ttf，然后将其放入Matplotlib 查找的mpl-data/fonts 目录中。这样就解决了问题。

Answer 3

I'm still having trouble installing Helvetica. I used fondu on the .dfont file and now have Helvetica.ttf in the mpl-data/fonts/ttf directory:

$ pwd
/Library/Frameworks/EPD64.framework/Versions/7.3/lib/python2.7/site-packages/matplotlib/mpl-data/fonts/ttf
$ ls
COPYRIGHT.TXT             RELEASENOTES.TXT          STIXSizFiveSymReg.ttf     Vera.ttf                  VeraSeBd.ttf
Helvetica.ttf             STIXGeneral.ttf           STIXSizFourSymBol.ttf     VeraBI.ttf                cmb10.ttf
HelveticaBold.ttf         STIXGeneralBol.ttf        STIXSizFourSymReg.ttf     VeraBd.ttf                cmex10.ttf
HelveticaBoldOblique.ttf  STIXGeneralBolIta.ttf     STIXSizOneSymBol.ttf      VeraIt.ttf                cmmi10.ttf
HelveticaLight.ttf        STIXGeneralItalic.ttf     STIXSizOneSymReg.ttf      VeraMoBI.ttf              cmr10.ttf
HelveticaLightOblique.ttf STIXNonUni.ttf            STIXSizThreeSymBol.ttf    VeraMoBd.ttf              cmss10.ttf
HelveticaOblique.ttf      STIXNonUniBol.ttf         STIXSizThreeSymReg.ttf    VeraMoIt.ttf              cmsy10.ttf
LICENSE_STIX              STIXNonUniBolIta.ttf      STIXSizTwoSymBol.ttf      VeraMono.ttf              cmtt10.ttf
README.TXT                STIXNonUniIta.ttf         STIXSizTwoSymReg.ttf      VeraSe.ttf

And I've edited my ~/.matplotlib/matplotlibrc file (which is the one loaded according to --verbose-debug ):

font.serif          : Palatino, Bitstream Vera Serif, New Century Schoolbook, Century Schoolbook L, Utopia, ITC Bookman, Bookman,
     Nimbus Roman No9 L, Times New Roman, Times, Palatino, Charter, serif
font.sans-serif     : Helvetica #, Bitstream Vera Sans, Lucida Grande, Verdana, Geneva, Lucid, Arial, Avant Garde, sans-serif

But I get this error when plotting:

/Library/Frameworks/EPD64.framework/Versions/7.3/lib/python2.7/site-packages/matplotlib/font_manager.py:1216: 
UserWarning: findfont: Font family ['sans-serif'] not found. Falling back to Bitstream Vera Sans
  (prop.get_family(), self.defaultFamily[fontext]))

If I set the default font as serif , Palatino shows up just fine.

Any tips?

Answer 4

In case it helps anyone, I wrote a script that automatically adds .ttf fonts from a custom folder to mpl-data . Place your .ttf files in some folder, and run this script to move them.

#!/usr/bin/env python3
# Imports
import os
import re
import shutil
from glob import glob
from matplotlib import matplotlib_fname
from matplotlib import get_cachedir

# Copy files over
_dir_data = re.sub('/matplotlibrc$', '', matplotlib_fname())
dir_source = '<your-font-directory-here>'
dir_dest = f'{_dir_data}/fonts/ttf'
# print(f'Transfering .ttf and .otf files from {dir_source} to {dir_dest}.')
for file in glob(f'{dir_source}/*.[ot]tf'):
    if not os.path.exists(f'{dir_dest}/{os.path.basename(file)}'):
        print(f'Adding font "{os.path.basename(file)}".')
        shutil.copy(file, dir_dest)

# Delete cache
dir_cache = get_cachedir()
for file in glob(f'{dir_cache}/*.cache') + glob(f'{dir_cache}/font*'):
    if not os.path.isdir(file): # don't dump the tex.cache folder... because dunno why
        os.remove(file)
        print(f'Deleted font cache {file}.')

---

This originally appeared in this stackoverflow post .