我正在尝试通过 matplotlib 创建一个 png，但我得到：
[Errno 2] No such file or directory
相同的代码适用于单元测试。print_figure来电
# creates a canvas from figure
canvas = FigureCanvasAgg(fig)
filename = "directory" + os.sep + name_prefix + ".png"
# saves figure to filesystem in png format
canvas.print_figure(filename)
我认为这可能是一个权限问题，但对我来说，相同的代码通过以下方式工作似乎很奇怪manage.py test
谢谢
My recommendation is to use fully qualified path names. For example: you could determine the MEDIA_ROOT from your django settings, write a snippet of code that ensures that a subdirectory for the graphs exists, then save the images there.
Your current code seems to rely on finding a subdirectory with the appropriate name in the "current working directory". The "current working directory" is a finicky thing - it will be different in testing, dev, production...
# import settings
from django.conf import settings
...
# ensure that a subdirectory with the appropriate name exists
if not os.path.exists(directory):
os.makedirs(directory)
# save the plots
canvas = FigureCanvasAgg(fig)
filename = settings.MEDIA_ROOT + os.sep + directory + os.sep + name_prefix + ".png"
# saves figure to filesystem in png format
canvas.print_figure(filename)
...
The actual location that you will save at should be determined by your needs. The key points are to use fully qualified paths and to check for the existence of the directory / subdirectory before attempting to save the image.