时间戳

首页 > 解决方案 > “TypeError：在使用 usetex:true 时，savefig 中需要一个类似字节的对象，而不是‘str’”

python - “TypeError：在使用 usetex:true 时，savefig 中需要一个类似字节的对象，而不是‘str’”

问题描述

在 matplotlib 中使用带有 text.usetex:true 的 savefig 时，我得到TypeError: a bytes-like object is required, not 'str'

编辑：我的解决方案是将 matplotlib 从 2.1.0 升级到 3.0.2

我可以使用 usetex:true 保存为 png 格式，但不能保存为 pdf 格式。我可以使用 usetex:false 保存为 pdf。这是产生错误所需的最少代码：

import matplotlib as mpl
mpl.use('pdf')
import matplotlib.pyplot as plt

mpl.rcParams['text.usetex'] = True
fig, axes = plt.subplots(1, 1)
fig.savefig('test.pdf')

我安装了 Miktex 2.9，以及此处提到的 dvipng 和 Ghostscript 的最新版本：https ://matplotlib.org/tutorials/text/usetex.html?highlight=usetex

我在路径中添加了以下内容：

C:\Program Files\gs\gs9.26\bin
C:\Program Files\MiKTeX 2.9\miktex\bin\x64

我正在使用 Windows 10、Python 3.6.3 和 matplotlib 2.1.0。

我还尝试删除我的 .matplotlib/tex.cache 目录，但没有成功。

完整追溯：

File ".\usetex.py", line 9, in <module>
    fig.savefig('test.pdf')
  File "C:\Users\bob\AppData\Local\Programs\Python\Python36-32\lib\site-packages\matplotlib\figure.py", line 1814, in savefig
    self.canvas.print_figure(fname, **kwargs)
  File "C:\Users\bob\AppData\Local\Programs\Python\Python36-32\lib\site-packages\matplotlib\backend_bases.py", line 2259, in print_figure
    **kwargs)
  File "C:\Users\bob\AppData\Local\Programs\Python\Python36-32\lib\site-packages\matplotlib\backends\backend_pdf.py", line 2592, in print_pdf
    self.figure.draw(renderer)
  File "C:\Users\bob\AppData\Local\Programs\Python\Python36-32\lib\site-packages\matplotlib\artist.py", line 55, in draw_wrapper
    return draw(artist, renderer, *args, **kwargs)
  File "C:\Users\bob\AppData\Local\Programs\Python\Python36-32\lib\site-packages\matplotlib\figure.py", line 1295, in draw
    renderer, self, artists, self.suppressComposite)
  File "C:\Users\bob\AppData\Local\Programs\Python\Python36-32\lib\site-packages\matplotlib\image.py", line 138, in _draw_list_compositing_images
    a.draw(renderer)
  File "C:\Users\bob\AppData\Local\Programs\Python\Python36-32\lib\site-packages\matplotlib\artist.py", line 55, in draw_wrapper
    return draw(artist, renderer, *args, **kwargs)
  File "C:\Users\bob\AppData\Local\Programs\Python\Python36-32\lib\site-packages\matplotlib\axes\_base.py", line 2399, in draw
    mimage._draw_list_compositing_images(renderer, self, artists)
  File "C:\Users\bob\AppData\Local\Programs\Python\Python36-32\lib\site-packages\matplotlib\image.py", line 138, in _draw_list_compositing_images
    a.draw(renderer)
  File "C:\Users\bob\AppData\Local\Programs\Python\Python36-32\lib\site-packages\matplotlib\artist.py", line 55, in draw_wrapper
    return draw(artist, renderer, *args, **kwargs)
  File "C:\Users\bob\AppData\Local\Programs\Python\Python36-32\lib\site-packages\matplotlib\axis.py", line 1138, in draw
    tick.draw(renderer)
  File "C:\Users\bob\AppData\Local\Programs\Python\Python36-32\lib\site-packages\matplotlib\artist.py", line 55, in draw_wrapper
    return draw(artist, renderer, *args, **kwargs)
  File "C:\Users\bob\AppData\Local\Programs\Python\Python36-32\lib\site-packages\matplotlib\axis.py", line 282, in draw
    self.label1.draw(renderer)
  File "C:\Users\bob\AppData\Local\Programs\Python\Python36-32\lib\site-packages\matplotlib\artist.py", line 55, in draw_wrapper
    return draw(artist, renderer, *args, **kwargs)
  File "C:\Users\bob\AppData\Local\Programs\Python\Python36-32\lib\site-packages\matplotlib\text.py", line 799, in draw
    mtext=mtext)
  File "C:\Users\bob\AppData\Local\Programs\Python\Python36-32\lib\site-packages\matplotlib\backends\backend_pdf.py", line 1944, in draw_tex
    pdfname = self.file.dviFontName(dvifont)
  File "C:\Users\bob\AppData\Local\Programs\Python\Python36-32\lib\site-packages\matplotlib\backends\backend_pdf.py", line 688, in dviFontName
    psfont = self.texFontMap[dvifont.texname]
  File "C:\Users\bob\AppData\Local\Programs\Python\Python36-32\lib\site-packages\matplotlib\dviread.py", line 866, in __getitem__
    fn = find_tex_file(fn)
  File "C:\Users\bob\AppData\Local\Programs\Python\Python36-32\lib\site-packages\matplotlib\dviread.py", line 1045, in find_tex_file
    stderr=subprocess.PIPE)
  File "C:\Users\bob\AppData\Local\Programs\Python\Python36-32\lib\subprocess.py", line 709, in __init__
    restore_signals, start_new_session)
  File "C:\Users\bob\AppData\Local\Programs\Python\Python36-32\lib\subprocess.py", line 971, in _execute_child
    args = list2cmdline(args)
  File "C:\Users\bob\AppData\Local\Programs\Python\Python36-32\lib\subprocess.py", line 461, in list2cmdline
    needquote = (" " in arg) or ("\t" in arg) or not arg
TypeError: a bytes-like object is required, not 'str'

标签： pythonmatplotlib

解决方案

感谢@ImportanceOfBeingErnest，我将 matplotlib 从 2.1.0 升级到 3.0.2，并且错误不再出现。

推荐阅读