Hello!
Bug summary
While trying to use matplotlib with custom subclass of datetime objects as x-values, a TypeError is raised.
It seems to exist a workaround using matplotlib.units: https://stackoverflow.com/a/10239347/2291710
However, I would like to know is it could be possible or not to support any subclass inherited from datetime natively (using issubclass() for example)? I tried to dig into the matplotlib source code but this is too complex for me.
The main use-case is for users of alternative datetime libraries like Pendulum or Arrow.
Code for reproduction
import datetime
import matplotlib.pyplot as plt
class MyDatetime(datetime.datetime):
pass
values = range(4)
datetimes = [MyDatetime.now() for _ in values]
fig, ax = plt.subplots()
ax.plot(datetimes, values)Actual outcome
Traceback (most recent call last):
File "C:\Users\delgan\Desktop\test.py", line 11, in <module>
ax.plot(datetimes, values)
File "C:\Users\delgan\AppData\Local\Programs\Python\Python36\lib\site-packages\matplotlib\__init__.py", line 1710, in inner
return func(ax, *args, **kwargs)
File "C:\Users\delgan\AppData\Local\Programs\Python\Python36\lib\site-packages\matplotlib\axes\_axes.py", line 1438, in plot
self.add_line(line)
File "C:\Users\delgan\AppData\Local\Programs\Python\Python36\lib\site-packages\matplotlib\axes\_base.py", line 1759, in add_line
self._update_line_limits(line)
File "C:\Users\delgan\AppData\Local\Programs\Python\Python36\lib\site-packages\matplotlib\axes\_base.py", line 1781, in _update_line_limits
path = line.get_path()
File "C:\Users\delgan\AppData\Local\Programs\Python\Python36\lib\site-packages\matplotlib\lines.py", line 951, in get_path
self.recache()
File "C:\Users\delgan\AppData\Local\Programs\Python\Python36\lib\site-packages\matplotlib\lines.py", line 652, in recache
x = _to_unmasked_float_array(xconv).ravel()
File "C:\Users\delgan\AppData\Local\Programs\Python\Python36\lib\site-packages\matplotlib\cbook\__init__.py", line 2008, in _to_unmasked_float_array
return np.asarray(x, float)
File "C:\Users\delgan\AppData\Local\Programs\Python\Python36\lib\site-packages\numpy\core\numeric.py", line 531, in asarray
return array(a, dtype, copy=False, order=order)
TypeError: float() argument must be a string or a number, not 'MyDatetime'
Expected outcome
There should be no error, and the graph should be plotted as if the dates was proper datetime objects.
Matplotlib version
- Operating system: WSL
- Matplotlib version: 2.1.0
- Matplotlib backen: TkAgg
- Python version: 3.6.4
Hello!
Bug summary
While trying to use
matplotlibwith custom subclass ofdatetimeobjects as x-values, aTypeErroris raised.It seems to exist a workaround using
matplotlib.units: https://stackoverflow.com/a/10239347/2291710However, I would like to know is it could be possible or not to support any subclass inherited from
datetimenatively (usingissubclass()for example)? I tried to dig into thematplotlibsource code but this is too complex for me.The main use-case is for users of alternative datetime libraries like
PendulumorArrow.Code for reproduction
Actual outcome
Expected outcome
There should be no error, and the graph should be plotted as if the dates was proper
datetimeobjects.Matplotlib version