matplotlib中的斜体字体标题不起作用

Question

import matplotlib.pyplot as plt
from textwrap import wrap

x_list = [11, 3, 6, 5]
label_list = ["red colour", "blue colour", "green colour", "back colour"]

title = "Some really really long long long title I really really need - and just can't - just can't - make it any - simply any - shorter - at all?"

newtitle = '\n'.join(wrap(title, width=50))  # wrap the long title so that it won't get cropped.

# here if I print `newtitle` first then "text below the main title" gets convert into italics
newtitle = "%s\n$%s$"%(newtitle, 'text\ below\ the\ main\ title') 
# but If I print `newtitle` after the secondary text it doesn't convert into italics
newtitle = "%s\n$%s$"%('text\ below\ the\ main\ title', newtitle)  # comment this line for 1st effect

plt.figure(figsize=(7,6), dpi=100)
plt.axis("equal")
plt.subplots_adjust(left=0.1, right=0.8, top=0.7)
plt.rc("font", size=10)
explode = [0.03, 0, 0, 0]

plt.pie(x_list, labels=label_list, explode=explode, autopct="%1.1f%%", startangle=90)
plt.title(newtitle, size=12)

plt.savefig('test.png')

所以我的主要问题是 -

辅助文本以普通字体排在第一位，然后主标题（newtitle）以斜体/浅色字体显示（看起来很漂亮）。

newtitle = "%s\n$%s$"%('text\ below\ the\ main\ title', newtitle)

我们可以不使用$签名吗？

Answer 1

这是预期的结果吗？

可以使用mathtext以快速而肮脏的方式完成此操作，但每行必须$剥落，例如：

newtitle = '\n'.join(['$%s$'%item for item in wrap(title, width=50)]).replace(' ', '\ ')
newtitle = "%s\n%s"%('text\ below\ the\ main\ title', newtitle)

但我认为更好看的方法是将这两个标题分开。您可以使用suptitle作为上一个，或者只使用text，无论哪种方式，您都可以独立控制其属性。 e.g：

plt.pie(x_list, labels=label_list, explode=explode, autopct="%1.1f%%", startangle=90)
plt.title('\n'.join(wrap(title, width=50)), size=12, style='italic')
plt.suptitle('some title', y=0.85, x=0.45) #y and x needed as you have adjusted the subplot size already.