Matplotlib 找不到无衬线字体系列

Question

这个代码

import numpy as np
import matplotlib.pyplot as plt
from matplotlib import rcParams

rcParams.update({
    'font.family':'sans-serif',
    'font.sans-serif':['Helvetica'],
    })

fig, ax = plt.subplots()
im = ax.matshow(np.random.rand(16,16))

plt.show()

给我以下警告：

/usr/lib64/python2.7/site-packages/matplotlib/font_manager.py:1288: UserWarning: 
findfont: Font family [u'sans-serif'] not found. Falling back to Bitstream Vera Sans
(prop.get_family(), self.defaultFamily[fontext]))

我已经检查并安装了 Helvetica：

/usr/share/fonts/100dpi/helvB12.pcf.gz: Helvetica:style=Bold
/usr/share/fonts/100dpi/helvR08.pcf.gz: Helvetica:style=Regular
/usr/share/fonts/100dpi/helvR10.pcf.gz: Helvetica:style=Regular
/usr/share/fonts/100dpi/helvR24-ISO8859-1.pcf.gz: Helvetica:style=Regular
/usr/share/fonts/100dpi/helvR18.pcf.gz: Helvetica:style=Regular
/usr/share/fonts/100dpi/helvO18-ISO8859-1.pcf.gz: Helvetica:style=Oblique
/usr/share/fonts/100dpi/helvO24.pcf.gz: Helvetica:style=Oblique
/usr/share/fonts/100dpi/helvB18.pcf.gz: Helvetica:style=Bold
/usr/share/fonts/100dpi/helvO14.pcf.gz: Helvetica:style=Oblique
/usr/share/fonts/100dpi/helvB08.pcf.gz: Helvetica:style=Bold
/usr/share/fonts/100dpi/helvB10.pcf.gz: Helvetica:style=Bold
/usr/share/fonts/100dpi/helvB12-ISO8859-1.pcf.gz: Helvetica:style=Bold
/usr/share/fonts/100dpi/helvB24-ISO8859-1.pcf.gz: Helvetica:style=Bold
/usr/share/fonts/100dpi/helvB08-ISO8859-1.pcf.gz: Helvetica:style=Bold
/usr/share/fonts/100dpi/helvB10-ISO8859-1.pcf.gz: Helvetica:style=Bold
/usr/share/fonts/100dpi/helvB14-ISO8859-1.pcf.gz: Helvetica:style=Bold
/usr/share/fonts/100dpi/helvR12.pcf.gz: Helvetica:style=Regular
/usr/share/fonts/100dpi/helvR12-ISO8859-1.pcf.gz: Helvetica:style=Regular
/usr/share/fonts/100dpi/helvBO14.pcf.gz: Helvetica:style=Bold Oblique
/usr/share/fonts/100dpi/helvR14-ISO8859-1.pcf.gz: Helvetica:style=Regular
/usr/share/fonts/100dpi/helvR08-ISO8859-1.pcf.gz: Helvetica:style=Regular
/usr/share/fonts/100dpi/helvR10-ISO8859-1.pcf.gz: Helvetica:style=Regular
/usr/share/fonts/100dpi/helvO12.pcf.gz: Helvetica:style=Oblique
/usr/share/fonts/100dpi/helvB18-ISO8859-1.pcf.gz: Helvetica:style=Bold
/usr/share/fonts/100dpi/helvR18-ISO8859-1.pcf.gz: Helvetica:style=Regular
/usr/share/fonts/100dpi/helvBO24.pcf.gz: Helvetica:style=Bold Oblique
/usr/share/fonts/100dpi/helvR14.pcf.gz: Helvetica:style=Regular
/usr/share/fonts/100dpi/helvBO18-ISO8859-1.pcf.gz: Helvetica:style=Bold Oblique
/usr/share/fonts/100dpi/helvBO12.pcf.gz: Helvetica:style=Bold Oblique
/usr/share/fonts/100dpi/helvBO12-ISO8859-1.pcf.gz: Helvetica:style=Bold Oblique
/usr/share/fonts/100dpi/helvO08.pcf.gz: Helvetica:style=Oblique
/usr/share/fonts/100dpi/helvO10.pcf.gz: Helvetica:style=Oblique
/usr/share/fonts/100dpi/helvBO14-ISO8859-1.pcf.gz: Helvetica:style=Bold Oblique
/usr/share/fonts/100dpi/helvBO08-ISO8859-1.pcf.gz: Helvetica:style=Bold Oblique
/usr/share/fonts/100dpi/helvBO10-ISO8859-1.pcf.gz: Helvetica:style=Bold Oblique
/usr/share/fonts/100dpi/helvR24.pcf.gz: Helvetica:style=Regular
/usr/share/fonts/100dpi/helvB14.pcf.gz: Helvetica:style=Bold
/usr/share/fonts/100dpi/helvO18.pcf.gz: Helvetica:style=Oblique
/usr/share/fonts/100dpi/helvO24-ISO8859-1.pcf.gz: Helvetica:style=Oblique
/usr/share/fonts/100dpi/helvB24.pcf.gz: Helvetica:style=Bold
/usr/share/fonts/100dpi/helvBO24-ISO8859-1.pcf.gz: Helvetica:style=Bold Oblique
/usr/share/fonts/100dpi/helvBO08.pcf.gz: Helvetica:style=Bold Oblique
/usr/share/fonts/100dpi/helvBO10.pcf.gz: Helvetica:style=Bold Oblique
/usr/share/fonts/100dpi/helvO12-ISO8859-1.pcf.gz: Helvetica:style=Oblique
/usr/share/fonts/100dpi/helvBO18.pcf.gz: Helvetica:style=Bold Oblique
/usr/share/fonts/100dpi/helvO14-ISO8859-1.pcf.gz: Helvetica:style=Oblique
/usr/share/fonts/100dpi/helvO08-ISO8859-1.pcf.gz: Helvetica:style=Oblique
/usr/share/fonts/100dpi/helvO10-ISO8859-1.pcf.gz: Helvetica:style=Oblique
/usr/share/fonts/100dpi/helvB12.pcf.gz: Helvetica:style=Bold
/usr/share/fonts/100dpi/helvR08.pcf.gz: Helvetica:style=Regular
/usr/share/fonts/100dpi/helvR10.pcf.gz: Helvetica:style=Regular
/usr/share/fonts/100dpi/helvR24-ISO8859-1.pcf.gz: Helvetica:style=Regular
/usr/share/fonts/100dpi/helvR18.pcf.gz: Helvetica:style=Regular
/usr/share/fonts/100dpi/helvO18-ISO8859-1.pcf.gz: Helvetica:style=Oblique
/usr/share/fonts/100dpi/helvO24.pcf.gz: Helvetica:style=Oblique
/usr/share/fonts/100dpi/helvB18.pcf.gz: Helvetica:style=Bold
/usr/share/fonts/100dpi/helvO14.pcf.gz: Helvetica:style=Oblique
/usr/share/fonts/100dpi/helvB08.pcf.gz: Helvetica:style=Bold
/usr/share/fonts/100dpi/helvB10.pcf.gz: Helvetica:style=Bold
/usr/share/fonts/100dpi/helvB12-ISO8859-1.pcf.gz: Helvetica:style=Bold
/usr/share/fonts/100dpi/helvB24-ISO8859-1.pcf.gz: Helvetica:style=Bold
/usr/share/fonts/100dpi/helvB08-ISO8859-1.pcf.gz: Helvetica:style=Bold
/usr/share/fonts/100dpi/helvB10-ISO8859-1.pcf.gz: Helvetica:style=Bold
/usr/share/fonts/100dpi/helvB14-ISO8859-1.pcf.gz: Helvetica:style=Bold
/usr/share/fonts/100dpi/helvR12.pcf.gz: Helvetica:style=Regular
/usr/share/fonts/100dpi/helvR12-ISO8859-1.pcf.gz: Helvetica:style=Regular
/usr/share/fonts/100dpi/helvBO14.pcf.gz: Helvetica:style=Bold Oblique
/usr/share/fonts/100dpi/helvR14-ISO8859-1.pcf.gz: Helvetica:style=Regular
/usr/share/fonts/100dpi/helvR08-ISO8859-1.pcf.gz: Helvetica:style=Regular
/usr/share/fonts/100dpi/helvR10-ISO8859-1.pcf.gz: Helvetica:style=Regular
/usr/share/fonts/100dpi/helvO12.pcf.gz: Helvetica:style=Oblique
/usr/share/fonts/100dpi/helvB18-ISO8859-1.pcf.gz: Helvetica:style=Bold
/usr/share/fonts/100dpi/helvR18-ISO8859-1.pcf.gz: Helvetica:style=Regular
/usr/share/fonts/100dpi/helvBO24.pcf.gz: Helvetica:style=Bold Oblique
/usr/share/fonts/100dpi/helvR14.pcf.gz: Helvetica:style=Regular
/usr/share/fonts/100dpi/helvBO18-ISO8859-1.pcf.gz: Helvetica:style=Bold Oblique
/usr/share/fonts/100dpi/helvBO12.pcf.gz: Helvetica:style=Bold Oblique
/usr/share/fonts/100dpi/helvBO12-ISO8859-1.pcf.gz: Helvetica:style=Bold Oblique
/usr/share/fonts/100dpi/helvO08.pcf.gz: Helvetica:style=Oblique
/usr/share/fonts/100dpi/helvO10.pcf.gz: Helvetica:style=Oblique
/usr/share/fonts/100dpi/helvBO14-ISO8859-1.pcf.gz: Helvetica:style=Bold Oblique
/usr/share/fonts/100dpi/helvBO08-ISO8859-1.pcf.gz: Helvetica:style=Bold Oblique
/usr/share/fonts/100dpi/helvBO10-ISO8859-1.pcf.gz: Helvetica:style=Bold Oblique
/usr/share/fonts/100dpi/helvR24.pcf.gz: Helvetica:style=Regular
/usr/share/fonts/100dpi/helvB14.pcf.gz: Helvetica:style=Bold
/usr/share/fonts/100dpi/helvO18.pcf.gz: Helvetica:style=Oblique
/usr/share/fonts/100dpi/helvO24-ISO8859-1.pcf.gz: Helvetica:style=Oblique
/usr/share/fonts/100dpi/helvB24.pcf.gz: Helvetica:style=Bold
/usr/share/fonts/100dpi/helvBO24-ISO8859-1.pcf.gz: Helvetica:style=Bold Oblique
/usr/share/fonts/100dpi/helvBO08.pcf.gz: Helvetica:style=Bold Oblique
/usr/share/fonts/100dpi/helvBO10.pcf.gz: Helvetica:style=Bold Oblique
/usr/share/fonts/100dpi/helvO12-ISO8859-1.pcf.gz: Helvetica:style=Oblique
/usr/share/fonts/100dpi/helvBO18.pcf.gz: Helvetica:style=Bold Oblique
/usr/share/fonts/100dpi/helvO14-ISO8859-1.pcf.gz: Helvetica:style=Oblique
/usr/share/fonts/100dpi/helvO08-ISO8859-1.pcf.gz: Helvetica:style=Oblique
/usr/share/fonts/100dpi/helvO10-ISO8859-1.pcf.gz: Helvetica:style=Oblique/usr/share/fonts/100dpi/helvB12.pcf.gz: Helvetica:style=Bold
/usr/share/fonts/100dpi/helvR08.pcf.gz: Helvetica:style=Regular
/usr/share/fonts/100dpi/helvR10.pcf.gz: Helvetica:style=Regular
/usr/share/fonts/100dpi/helvR24-ISO8859-1.pcf.gz: Helvetica:style=Regular
/usr/share/fonts/100dpi/helvR18.pcf.gz: Helvetica:style=Regular
/usr/share/fonts/100dpi/helvO18-ISO8859-1.pcf.gz: Helvetica:style=Oblique
/usr/share/fonts/100dpi/helvO24.pcf.gz: Helvetica:style=Oblique
/usr/share/fonts/100dpi/helvB18.pcf.gz: Helvetica:style=Bold
/usr/share/fonts/100dpi/helvO14.pcf.gz: Helvetica:style=Oblique
/usr/share/fonts/100dpi/helvB08.pcf.gz: Helvetica:style=Bold
/usr/share/fonts/100dpi/helvB10.pcf.gz: Helvetica:style=Bold
/usr/share/fonts/100dpi/helvB12-ISO8859-1.pcf.gz: Helvetica:style=Bold
/usr/share/fonts/100dpi/helvB24-ISO8859-1.pcf.gz: Helvetica:style=Bold
/usr/share/fonts/100dpi/helvB08-ISO8859-1.pcf.gz: Helvetica:style=Bold
/usr/share/fonts/100dpi/helvB10-ISO8859-1.pcf.gz: Helvetica:style=Bold
/usr/share/fonts/100dpi/helvB14-ISO8859-1.pcf.gz: Helvetica:style=Bold
/usr/share/fonts/100dpi/helvR12.pcf.gz: Helvetica:style=Regular
/usr/share/fonts/100dpi/helvR12-ISO8859-1.pcf.gz: Helvetica:style=Regular
/usr/share/fonts/100dpi/helvBO14.pcf.gz: Helvetica:style=Bold Oblique
/usr/share/fonts/100dpi/helvR14-ISO8859-1.pcf.gz: Helvetica:style=Regular
/usr/share/fonts/100dpi/helvR08-ISO8859-1.pcf.gz: Helvetica:style=Regular
/usr/share/fonts/100dpi/helvR10-ISO8859-1.pcf.gz: Helvetica:style=Regular
/usr/share/fonts/100dpi/helvO12.pcf.gz: Helvetica:style=Oblique
/usr/share/fonts/100dpi/helvB18-ISO8859-1.pcf.gz: Helvetica:style=Bold
/usr/share/fonts/100dpi/helvR18-ISO8859-1.pcf.gz: Helvetica:style=Regular
/usr/share/fonts/100dpi/helvBO24.pcf.gz: Helvetica:style=Bold Oblique
/usr/share/fonts/100dpi/helvR14.pcf.gz: Helvetica:style=Regular
/usr/share/fonts/100dpi/helvBO18-ISO8859-1.pcf.gz: Helvetica:style=Bold Oblique
/usr/share/fonts/100dpi/helvBO12.pcf.gz: Helvetica:style=Bold Oblique
/usr/share/fonts/100dpi/helvBO12-ISO8859-1.pcf.gz: Helvetica:style=Bold Oblique
/usr/share/fonts/100dpi/helvO08.pcf.gz: Helvetica:style=Oblique
/usr/share/fonts/100dpi/helvO10.pcf.gz: Helvetica:style=Oblique
/usr/share/fonts/100dpi/helvBO14-ISO8859-1.pcf.gz: Helvetica:style=Bold Oblique
/usr/share/fonts/100dpi/helvBO08-ISO8859-1.pcf.gz: Helvetica:style=Bold Oblique
/usr/share/fonts/100dpi/helvBO10-ISO8859-1.pcf.gz: Helvetica:style=Bold Oblique
/usr/share/fonts/100dpi/helvR24.pcf.gz: Helvetica:style=Regular
/usr/share/fonts/100dpi/helvB14.pcf.gz: Helvetica:style=Bold
/usr/share/fonts/100dpi/helvO18.pcf.gz: Helvetica:style=Oblique
/usr/share/fonts/100dpi/helvO24-ISO8859-1.pcf.gz: Helvetica:style=Oblique
/usr/share/fonts/100dpi/helvB24.pcf.gz: Helvetica:style=Bold
/usr/share/fonts/100dpi/helvBO24-ISO8859-1.pcf.gz: Helvetica:style=Bold Oblique
/usr/share/fonts/100dpi/helvBO08.pcf.gz: Helvetica:style=Bold Oblique
/usr/share/fonts/100dpi/helvBO10.pcf.gz: Helvetica:style=Bold Oblique
/usr/share/fonts/100dpi/helvO12-ISO8859-1.pcf.gz: Helvetica:style=Oblique
/usr/share/fonts/100dpi/helvBO18.pcf.gz: Helvetica:style=Bold Oblique
/usr/share/fonts/100dpi/helvO14-ISO8859-1.pcf.gz: Helvetica:style=Oblique
/usr/share/fonts/100dpi/helvO08-ISO8859-1.pcf.gz: Helvetica:style=Oblique
/usr/share/fonts/100dpi/helvO10-ISO8859-1.pcf.gz: Helvetica:style=Oblique

我也看到了，我也多次删除fontList.cache，都没有用

如何将我的字体更改为 Helvetica？

Answer 1

显然这是因为我的字体是 .pcf，而您需要 .ttf 才能用它们实际书写。由于许可问题，至少在 Gentoo 下，无法通过包管理器使用 Helvetica。

我的解决方案是安装 media-fonts/liberation-fonts，这是用于 Liberation 字体的 Gentoo 软件包。 Liberation Sans 是 Helvetica 的一个相当不错的替代品。

以下代码片段基本上修复了我的示例：

rcParams.update({
    'font.family':'sans-serif',
    'font.sans-serif':['Liberation Sans'],
    })

Matplotlib 找不到无衬线字体系列

Matplotlib cannot find sans-serif family

fonts

gentoo

matplotlib