Python 使用简单打印脚本时出现属性错误

我试图用Python绘制一个简单的函数。我使用以下代码：

# lineplot.py
import numpy as np
import pylab as pl
# Make an array of x values
x = [1, 2, 3, 4, 5]
# Make an array of y values for each x value
y = [1, 4, 9, 16, 25]
# use pylab to plot x and y
pl.plot(x, y)
# show the plot on the screen
pl.show()

但是，我希望看到输出的最后一行出现以下错误：

AttributeError: 'NoneType' object has no attribute 'get_default_size'

有人知道我哪里出错了吗

错误的完整回溯：

>>> pl.show()
Traceback (most recent call last):
    File "/usr/lib64/python2.7/site-packages/matplotlib/backends/backend_gtk.py", line 394,\    in expose_event
    self._render_figure(self._pixmap, w, h)
    File "/usr/lib64/python2.7/site-packages/matplotlib/backends/backend_gtkagg.py", line 75, in _render_figure
    FigureCanvasAgg.draw(self)
    File "/usr/lib64/python2.7/site-packages/matplotlib/backends/backend_agg.py", line 394, in draw
    self.figure.draw(self.renderer)
    File "/usr/lib64/python2.7/site-packages/matplotlib/artist.py", line 55, in draw_wrapper
    draw(artist, renderer, *args, **kwargs)
    File "/usr/lib64/python2.7/site-packages/matplotlib/figure.py", line 798, in draw
    func(*args)
    File "/usr/lib64/python2.7/site-packages/matplotlib/artist.py", line 55, in draw_wrapper
    draw(artist, renderer, *args, **kwargs)
    File "/usr/lib64/python2.7/site-packages/matplotlib/axes.py", line 1946, in draw
    a.draw(renderer)
    File "/usr/lib64/python2.7/site-packages/matplotlib/artist.py", line 55, in draw_wrapper
    draw(artist, renderer, *args, **kwargs)
    File "/usr/lib64/python2.7/site-packages/matplotlib/axis.py", line 1017, in draw
    tick.draw(renderer)
    File "/usr/lib64/python2.7/site-packages/matplotlib/artist.py", line 55, in draw_wrapper
    draw(artist, renderer, *args, **kwargs)
    File "/usr/lib64/python2.7/site-packages/matplotlib/axis.py", line 234, in draw
    self.label1.draw(renderer)
    File "/usr/lib64/python2.7/site-packages/matplotlib/artist.py", line 55, in draw_wrapper
    draw(artist, renderer, *args, **kwargs)
    File "/usr/lib64/python2.7/site-packages/matplotlib/text.py", line 526, in draw
    bbox, info = self._get_layout(renderer)
    File "/usr/lib64/python2.7/site-packages/matplotlib/text.py", line 300, in _get_layout
    ismath=False)
    File "/usr/lib64/python2.7/site-packages/matplotlib/backends/backend_agg.py", line 180, in get_text_width_height_descent
    font = self._get_agg_font(prop)
    File "/usr/lib64/python2.7/site-packages/matplotlib/backends/backend_agg.py", line 226, in _get_agg_font
    size = prop.get_size_in_points()
    File "/usr/lib64/python2.7/site-packages/matplotlib/font_manager.py", line 798, in get_size_in_points
    default_size = fontManager.get_default_size()
    AttributeError: 'NoneType' object has no attribute 'get_default_size'
    Traceback (most recent call last):
    File "/usr/lib64/python2.7/site-packages/matplotlib/backends/backend_gtk.py", line 394, in expose_event
    self._render_figure(self._pixmap, w, h)
    File "/usr/lib64/python2.7/site-packages/matplotlib/backends/backend_gtkagg.py", line 75, in _render_figure
    FigureCanvasAgg.draw(self)
    File "/usr/lib64/python2.7/site-packages/matplotlib/backends/backend_agg.py", line 394, in draw
    self.figure.draw(self.renderer)
    File "/usr/lib64/python2.7/site-packages/matplotlib/artist.py", line 55, in draw_wrapper
    draw(artist, renderer, *args, **kwargs)
    File "/usr/lib64/python2.7/site-packages/matplotlib/figure.py", line 798, in draw
    func(*args)
    File "/usr/lib64/python2.7/site-packages/matplotlib/artist.py", line 55, in draw_wrapper
    draw(artist, renderer, *args, **kwargs)
    File "/usr/lib64/python2.7/site-packages/matplotlib/axes.py", line 1946, in draw
    a.draw(renderer)
    File "/usr/lib64/python2.7/site-packages/matplotlib/artist.py", line 55, in draw_wrapper
    draw(artist, renderer, *args, **kwargs)
    File "/usr/lib64/python2.7/site-packages/matplotlib/axis.py", line 1017, in draw
    tick.draw(renderer)
    File "/usr/lib64/python2.7/site-packages/matplotlib/artist.py", line 55, in draw_wrapper
    draw(artist, renderer, *args, **kwargs)
    File "/usr/lib64/python2.7/site-packages/matplotlib/axis.py", line 234, in draw
    self.label1.draw(renderer)
    File "/usr/lib64/python2.7/site-packages/matplotlib/artist.py", line 55, in draw_wrapper
    draw(artist, renderer, *args, **kwargs)
    File "/usr/lib64/python2.7/site-packages/matplotlib/text.py", line 526, in draw
    bbox, info = self._get_layout(renderer)
    File "/usr/lib64/python2.7/site-packages/matplotlib/text.py", line 300, in _get_layout
    ismath=False)
    File "/usr/lib64/python2.7/site-packages/matplotlib/backends/backend_agg.py", line 180, in get_text_width_height_descent
    font = self._get_agg_font(prop)
    File "/usr/lib64/python2.7/site-packages/matplotlib/backends/backend_agg.py", line 226, in _get_agg_font
    size = prop.get_size_in_points()
    File "/usr/lib64/python2.7/site-packages/matplotlib/font_manager.py", line 798, in get_size_in_points
    default_size = fontManager.get_default_size()
    AttributeError: 'NoneType' object has no attribute 'get_default_size'
    Traceback (most recent call last):
    File "/usr/lib64/python2.7/site-packages/matplotlib/backends/backend_gtk.py", line 394, in expose_event
    self._render_figure(self._pixmap, w, h)
    File "/usr/lib64/python2.7/site-packages/matplotlib/backends/backend_gtkagg.py", line 75, in _render_figure
    FigureCanvasAgg.draw(self)
    File "/usr/lib64/python2.7/site-packages/matplotlib/backends/backend_agg.py", line 394, in draw
    self.figure.draw(self.renderer)
    File "/usr/lib64/python2.7/site-packages/matplotlib/artist.py", line 55, in draw_wrapper
    draw(artist, renderer, *args, **kwargs)
    File "/usr/lib64/python2.7/site-packages/matplotlib/figure.py", line 798, in draw
    func(*args)
    File "/usr/lib64/python2.7/site-packages/matplotlib/artist.py", line 55, in draw_wrapper
    draw(artist, renderer, *args, **kwargs)
    File "/usr/lib64/python2.7/site-packages/matplotlib/axes.py", line 1946, in draw
    a.draw(renderer)
    File "/usr/lib64/python2.7/site-packages/matplotlib/artist.py", line 55, in draw_wrapper
    draw(artist, renderer, *args, **kwargs)
    File "/usr/lib64/python2.7/site-packages/matplotlib/axis.py", line 1017, in draw
    tick.draw(renderer)
    File "/usr/lib64/python2.7/site-packages/matplotlib/artist.py", line 55, in draw_wrapper
    draw(artist, renderer, *args, **kwargs)
    File "/usr/lib64/python2.7/site-packages/matplotlib/axis.py", line 234, in draw
    self.label1.draw(renderer)
    File "/usr/lib64/python2.7/site-packages/matplotlib/artist.py", line 55, in draw_wrapper
    draw(artist, renderer, *args, **kwargs)
    File "/usr/lib64/python2.7/site-packages/matplotlib/text.py", line 526, in draw
    bbox, info = self._get_layout(renderer)
    File "/usr/lib64/python2.7/site-packages/matplotlib/text.py", line 300, in _get_layout
    ismath=False)
    File "/usr/lib64/python2.7/site-packages/matplotlib/backends/backend_agg.py", line 180, in get_text_width_height_descent
    font = self._get_agg_font(prop)
    File "/usr/lib64/python2.7/site-packages/matplotlib/backends/backend_agg.py", line 226, in _get_agg_font
    size = prop.get_size_in_points()
    File "/usr/lib64/python2.7/site-packages/matplotlib/font_manager.py", line 798, in get_size_in_points
    default_size = fontManager.get_default_size()
    AttributeError: 'NoneType' object has no attribute 'get_default_size'

---

问题是OP使用的

matplotlib

版本（1.0.1）。升级它解决了问题（如聊天中的讨论所述）

这就是我们解决问题的方法（它应该在Linux上工作）：

从中下载最新的

matplotlib

tar文件

解压缩tar.gz归档文件

将cd放入matplotlib目录

跑

python setup.py build

如果它无法抱怨某些头文件（例如

png.h

），请从系统存储库安装相关的

-devel

软件包。当然需要

python-devel

和

libpng12-devel

跑

python setup.py install --user

它将在

$HOME/.local/lib/pythonX.X/site软件包中安装matplotlib。此目录在系统范围内的任何目录之前加载到python路径中。此外，系统范围内的安装也不会出现混乱的风险

---

您使用的python和matplotlib的版本是什么？这里的代码运行正常，因此可能存在其他问题。您是否可以尝试直接使用matplotlib而不是通过pylab？i、 e.

导入matplotlib.pyplot作为pl

而不是

导入pylab作为pl

？@M4rtini我会说这是我的后端，或者我用来在其中绘图的任何设备。python的版本是2.7。Matplotlib是1.0版。1@HannesOvrén-当我直接使用matplotlib时，仍然会遇到相同的错误。您使用的是什么后端？您应该从

python-c'import matplotlib获取它；打印（matplotlib.backends.backend）