Matplotlib support

[BrechtBa]

Could matplotlib support be added?

import pendulum
import matplotlib.pyplot as plt
datetimes = [
    pendulum.datetime(2018, 5, 1, tz='UTC'),
    pendulum.datetime(2018, 5, 2, tz='UTC'),
    pendulum.datetime(2018, 5, 3, tz='UTC'),
    pendulum.datetime(2018, 5, 4, tz='UTC')
]
values = [0, 1, 2, 3]
fig, ax = plt.subplots()
ax.plot(datetimes, values)

Results in:

TypeError: float() argument must be a string or a number, not 'Pendulum'

The above code is supported by the standard datetime package.

[sdispater]

Strange. It should work since Pendulum's datetime objects inherit directly from native datetime ones.

Could you provide the full stacktrace to see exactly where the error is coming from?

[BrechtBa]

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python3.5/dist-packages/matplotlib/__init__.py", line 1898, in inner
    return func(ax, *args, **kwargs)
  File "/usr/local/lib/python3.5/dist-packages/matplotlib/axes/_axes.py", line 1407, in plot
    self.add_line(line)
  File "/usr/local/lib/python3.5/dist-packages/matplotlib/axes/_base.py", line 1793, in add_line
    self._update_line_limits(line)
  File "/usr/local/lib/python3.5/dist-packages/matplotlib/axes/_base.py", line 1815, in _update_line_limits
    path = line.get_path()
  File "/usr/local/lib/python3.5/dist-packages/matplotlib/lines.py", line 989, in get_path
    self.recache()
  File "/usr/local/lib/python3.5/dist-packages/matplotlib/lines.py", line 676, in recache
    x = np.asarray(xconv, np.float_)
  File "/usr/local/lib/python3.5/dist-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 'Pendulum'

[Delgan]

Matplotlib doesn't handle datetime subclasses very well: https://github.com/matplotlib/matplotlib/issues/11275

There is a workaround though:

import pendulum
import matplotlib.dates as mdates
import matplotlib.units as munits

munits.registry[pendulum.datetime] = mdates.DateConverter()