Issue 1:
Python 3.7.5 (default, Oct 31 2019, 15:18:51) [MSC v.1916 64 bit (AMD64)] :: Anaconda, Inc. on win32,

import seaborn as sns

import numpy as np

sns.version

'0.9.0'

np.version

'1.18.1'

sns.palplot(sns.diverging_palette(150, 275, s=80, l=55, n=9))

Traceback (most recent call last):

File "C:\Users\Test.conda\envs\Python37\lib\site-packages\numpy\core\function_base.py", line 117, in linspace

num = operator.index(num)

TypeError: 'float' object cannot be interpreted as an integer

During handling of the above exception, another exception occurred:

Traceback (most recent call last):

File "C:\Users\Test.conda\envs\Python37\lib\site-packages\seaborn\palettes.py", line 744, in diverging_palette

neg = palfunc((h_neg, s, l), 128 - (sep / 2), reverse=True, input="husl")

File "C:\Users\Test.conda\envs\Python37\lib\site-packages\seaborn\palettes.py", line 641, in light_palette

return blend_palette(colors, n_colors, as_cmap)

File "C:\Users\Test.conda\envs\Python37\lib\site-packages\seaborn\palettes.py", line 777, in blend_palette

pal = _ColorPalette(pal(np.linspace(0, 1, n_colors)))

File "<array_function internals>", line 6, in linspace

File "C:\Users\Test.conda\envs\Python37\lib\site-packages\numpy\core\function_base.py", line 121, in linspace.format(type(num)))

TypeError: object of type <class 'float'> cannot be safely interpreted as an integer.

Issue 2:
python: 3.6.9

seaborn version: 0.9.0

matplotlib version: 3.1.2

matplotlib backend: module://ipykernel.pylab.backend_inline

Trying to get a diverging palette and running code from documentation:

https://seaborn.pydata.org/generated/seaborn.diverging_palette.html

import seaborn as sns; sns.set()
sns.palplot(sns.diverging_palette(240, 10, n=9))

Error:

---------------------------------------------------------------------------
TypeError Traceback (most recent call last)
~/.local/lib/python3.6/site-packages/numpy/core/function_base.py in linspace(start, stop, num, endpoint, retstep, dtype, axis)
116 try:
--> 117 num = operator.index(num)
118 except TypeError:

TypeError: 'float' object cannot be interpreted as an integer

During handling of the above exception, another exception occurred:

TypeError Traceback (most recent call last)
<ipython-input-10-3b31105fd99b> in <module>
1 import seaborn as sns; sns.set()
----> 2 sns.palplot(sns.diverging_palette(240, 10, n=9))

~/.local/lib/python3.6/site-packages/seaborn/palettes.py in diverging_palette(h_neg, h_pos, s, l, sep, n, center, as_cmap)
742 """
743 palfunc = dark_palette if center == "dark" else light_palette
--> 744 neg = palfunc((h_neg, s, l), 128 - (sep / 2), reverse=True, input="husl")
745 pos = palfunc((h_pos, s, l), 128 - (sep / 2), input="husl")
746 midpoint = dict(light=[(.95, .95, .95, 1.)],

~/.local/lib/python3.6/site-packages/seaborn/palettes.py in light_palette(color, n_colors, reverse, as_cmap, input)
639 light = set_hls_values(color, l=.95) # noqa
640 colors = [color, light] if reverse else [light, color]
--> 641 return blend_palette(colors, n_colors, as_cmap)
642
643

~/.local/lib/python3.6/site-packages/seaborn/palettes.py in blend_palette(colors, n_colors, as_cmap, input)
775 pal = mpl.colors.LinearSegmentedColormap.from_list(name, colors)
776 if not as_cmap:
--> 777 pal = _ColorPalette(pal(np.linspace(0, 1, n_colors)))
778 return pal
779

<__array_function__ internals> in linspace(*args, **kwargs)

~/.local/lib/python3.6/site-packages/numpy/core/function_base.py in linspace(start, stop, num, endpoint, retstep, dtype, axis)
119 raise TypeError(
120 "object of type {} cannot be safely interpreted as an integer."
--> 121 .format(type(num)))
122
123 if num < 0:

TypeError: object of type <class 'float'> cannot be safely interpreted as an integer.

looks like its due to line 744 the 128 - (sep / 2) produces a float

next line will also have issue