我刚刚注意到,当我尝试在 NCAR 的 Cheyenne 超级计算机上导入metpy.plots 时,它在使用metpy 0.10.0(使用Cartopy 0.17.0)时加载并正常工作,但使用metpy 0.12.0 或0.12.1 时出现错误(使用 Cartopy 0.18.0b2)。这是我得到的错误:
(NPL) jaredlee@cheyenne3:~> python3
Python 3.6.8 (default, Jun 27 2019, 20:02:05)
[GCC 8.3.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import metpy
>>> metpy.__version__
'0.12.1'
>>> import metpy.plots as mpplots
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/glade/work/jaredlee/python/my_npl_clone_20200417/lib/python3.6/site-packages/metpy/plots/__init__.py", line 27, in <module>
from .cartopy_utils import USCOUNTIES, USSTATES
File "/glade/work/jaredlee/python/my_npl_clone_20200417/lib/python3.6/site-packages/metpy/plots/cartopy_utils.py", line 43, in <module>
USCOUNTIES = MetPyMapFeature('us_counties', '20m', facecolor='None', edgecolor='black')
File "/glade/work/jaredlee/python/my_npl_clone_20200417/lib/python3.6/site-packages/metpy/plots/cartopy_utils.py", line 16, in __init__
super().__init__('', name, scale, **kwargs)
File "/glade/work/jaredlee/python/my_npl_clone_20200417/lib/python3.6/site-packages/cartopy/feature/__init__.py", line 264, in __init__
self._validate_scale()
File "/glade/work/jaredlee/python/my_npl_clone_20200417/lib/python3.6/site-packages/cartopy/feature/__init__.py", line 274, in _validate_scale
'Valid scales are "110m", "50m", and "10m".'
ValueError: 20m is not a valid Natural Earth scale. Valid scales are "110m", "50m", and "10m".
>>>
如果我在我的本地metpy 副本中手动更改cartopy_utils.py,以便USCOUNTIES 和USSTATES 函数调用MetPyMapFeature 使用'10m' 而不是'20m',那么错误就会消失。这是 cartopy_utils.py 中的“20m”错误吗?Natural Earth 的网页宣传它提供 1:10m、1:50m 和 1:110m 比例的数据。