matplotlib源码解析标题实现(窗口标题，标题，子图标题不同之间的差异)

import matplotlib.pyplot as plt

plt.rcParams['font.sans-serif'] = 'SimHei'

fig = plt.figure()
plt.plot([1, 2])
# 设置图像标题
plt.suptitle("这是图像标题")
# 设置子图标题
plt.title("这是子图标题")
# 获取默认窗口标题
current_title = fig.canvas.manager.window.windowTitle()
print("默认窗口：",current_title)
# 设置窗口标题方式一
fig.canvas.set_window_title("这是窗口标题")
# 设置窗口标题方式二
fig.canvas.manager.window.setWindowTitle("这是窗口标题")

plt.show()

import matplotlib.pyplot as plt

plt.rcParams['font.sans-serif'] = 'SimHei'

fig = plt.figure()
plt.subplot(1, 2, 1)
plt.plot([1,2,3,4], [1,4,9,16], "go") 
# 设置子图1标题
plt.title("子图1标题")

plt.subplot(122)
plt.plot([1,2,3,4], [1,4,9,16], "r^") # r^ 表示 红色(red)三角
# 设置子图2标题
plt.title("子图2标题")
# 设置图像标题
plt.suptitle("图像标题")
# 设置窗口标题
#fig.canvas.set_window_title("这是窗口标题")
fig.canvas.manager.window.setWindowTitle("这是窗口标题")

plt.show()

import matplotlib.pyplot as plt

plt.rcParams['font.sans-serif'] = 'SimHei'

fig, ax = plt.subplots(nrows=1, ncols=2, figsize=(6,6))
ax[0].plot([1,2,3,4], [1,4,9,16], "go") 
# 设置子图1标题
ax[0].set_title("子图1标题") 
ax[1].plot([1,2,3,4], [1,4,9,16], "r^") 
# 设置子图2标题
ax[1].set_title("子图2标题") 
# 设置图像标题
plt.suptitle("图像标题")
# 设置窗口标题
fig.canvas.manager.window.setWindowTitle("这是窗口标题")

plt.show()

class FigureManagerQT(FigureManagerBase):
  def set_window_title(self, title):
    self.window.setWindowTitle(title)

  def suptitle(self, t, **kwargs):
    """
    Add a centered title to the figure.

    Parameters
    ----------
    t : str
      The title text.

    x : float, default 0.5
      The x location of the text in figure coordinates.

    y : float, default 0.98
      The y location of the text in figure coordinates.

    horizontalalignment, ha : {'center', 'left', right'}, default: 'center'
      The horizontal alignment of the text relative to (*x*, *y*).

    verticalalignment, va : {'top', 'center', 'bottom', 'baseline'}, \
default: 'top'
      The vertical alignment of the text relative to (*x*, *y*).

    fontsize, size : default: :rc:`figure.titlesize`
      The font size of the text. See `.Text.set_size` for possible
      values.

    fontweight, weight : default: :rc:`figure.titleweight`
      The font weight of the text. See `.Text.set_weight` for possible
      values.

    Returns
    -------
    text
      The `.Text` instance of the title.

    Other Parameters
    ----------------
    fontproperties : None or dict, optional
      A dict of font properties. If *fontproperties* is given the
      default values for font size and weight are taken from the
      `.FontProperties` defaults. :rc:`figure.titlesize` and
      :rc:`figure.titleweight` are ignored in this case.

    **kwargs
      Additional kwargs are `matplotlib.text.Text` properties.

    Examples
    --------
    >>> fig.suptitle('This is the figure title', fontsize=12)
    """

def title(label, fontdict=None, loc=None, pad=None, *, y=None, **kwargs):
  return gca().set_title(
    label, fontdict=fontdict, loc=loc, pad=pad, y=y, **kwargs)

Axes.set_title(self, label, fontdict=None, loc=None, pad=None, *, y=None, **kwargs):
  """
  Set a title for the axes.

  Set one of the three available axes titles. The available titles
  are positioned above the axes in the center, flush with the left
  edge, and flush with the right edge.

  Parameters
  ----------
  label : str
    Text to use for the title

  fontdict : dict
    A dictionary controlling the appearance of the title text,
    the default *fontdict* is::

      {'fontsize': rcParams['axes.titlesize'],
      'fontweight': rcParams['axes.titleweight'],
      'color': rcParams['axes.titlecolor'],
      'verticalalignment': 'baseline',
      'horizontalalignment': loc}

  loc : {'center', 'left', 'right'}, default: :rc:`axes.titlelocation`
    Which title to set.

  y : float, default: :rc:`axes.titley`
    Vertical axes loation for the title (1.0 is the top). If
    None (the default), y is determined automatically to avoid
    decorators on the axes.

  pad : float, default: :rc:`axes.titlepad`
    The offset of the title from the top of the axes, in points.

  Returns
  -------
  `.Text`
    The matplotlib text instance representing the title

  Other Parameters
  ----------------
  **kwargs : `.Text` properties
    Other keyword arguments are text properties, see `.Text` for a list
    of valid text properties.
  """

import matplotlib.pyplot as plt

plt.rcParams['font.sans-serif'] = 'SimHei'

fig, ax = plt.subplots(nrows=1, ncols=2, figsize=(6,6))
ax[0].plot([1,2,3,4], [1,4,9,16], "go") 
ax[1].plot([1,2,3,4], [1,4,9,16], "r^") 

print(plt.gca())
print(ax[0],ax[1])