AttributeError: module 'numpy' has no attribute 'float'.

[quickbrett]

This small example retrurns an error

import numpy as np
import matplotlib.pyplot as plt
from mpl_toolkits.basemap import Basemap

fig = plt.figure(figsize=(8, 6), edgecolor="w")
m = Basemap(projection="moll", resolution=None, lat_0=0, lon_0=0)
m.drawmapboundary()
m.shadedrelief(scale=0.2)

The error message:

AttributeError: module 'numpy' has no attribute 'float'.
`np.float` was a deprecated alias for the builtin `float`. To avoid this error in existing code, use `float` by itself. Doing this will not modify any behavior and is safe. If you specifically wanted the numpy scalar type, use `np.float64` here.
The aliases was originally deprecated in NumPy 1.20; for more details and guidance see the original release note at:
    https://numpy.org/devdocs/release/1.20.0-notes.html#deprecations

I belive, the wrong attribute is used in packages/basemap/src/mpl_toolkits/basemap/__init__.py, master branch, line 4186.

This small patch works for me:

4186c4186
<                     x1 = np.array(ny*[0.5*(self.xmax + self.xmin)],np.float)
---
>                     x1 = np.array(ny*[0.5*(self.xmax + self.xmin)],np.float32)

Thanks for the great package!

[molinav]

Thanks for pointing the bug! Just out of curiosity, which numpy version are you using?

[quickbrett]

I'm using the following versions:

• matplotlib 3.7.3
• numpy 1.25.2
• basemap 1.3.8

[moritzhuetten]

@quickbrett thanks for raising this issue and proposing the fix and @molinav thanks for maintaining this still great package. I actually got the same error, I think it is related to the latest numpy versions.

[molinav]

It seems that numpy.float was removed with its release 1.24.0 (https://numpy.org/devdocs/release/1.24.0-notes.html). I will replace it with the Python builtin float as suggested in the link.

Hopefully I can get some time soon to start a basic unit test collection, because these issues would be identified immediately with the automatic tests.

[molinav]

@quickbrett I just added the patch in a hotfix branch (1.3.9), your small example now works after the correction. I took this moment to correct all the references to numpy.float that I found in the whole library, mostly replaced with numpy.float64.

I am not sure when I will release 1.3.9, maybe I will do a couple of bugfixes more that are still around before tagging.

[quickbrett]

@molinav I installes the hotfix branch

pip install git+https://github.com/matplotlib/basemap@hotfix-1.3.9#subdirectory=packages/basemap

Hence I'm using the following package versions (pip list):

• basemap 1.3.9
• numpy 1.25.2
• matplotlib 3.7.3

I tested the new version with a few simple examples and it worked for me.

Thanks!

[molinav]

@quickbrett I have just added a couple of unit tests for Basemap.shadedrelief based on your snippet, so I am finally closing this issue. The bugfix will come with basemap 1.3.9 (hopefully soon).