Fix: Complete patch for np.float/np.int removal in numpy>=1.24 (11 affected files)

[znatri]

Summary

madmom 0.16.1 uses deprecated np.float and np.int aliases removed in NumPy 1.24. This makes madmom unusable with any modern NumPy version.

This is a known issue (#527), but most workarounds only address the first file that crashes (io/__init__.py). The bare aliases actually exist in 11 files across the package, so partial patches still fail at runtime.

Error

>>> from madmom.features import DBNDownBeatTrackingProcessor
AttributeError: module 'numpy' has no attribute 'float'.
`np.float` was a deprecated alias for the builtin `float`.

All Affected Files

File	Aliases
madmom/io/__init__.py	np.float
madmom/evaluation/__init__.py	np.float, np.int
madmom/evaluation/beats.py	np.float
madmom/evaluation/chords.py	np.float, np.int
madmom/features/beats.py	np.float, np.int
madmom/features/notes.py	np.float
madmom/features/onsets.py	np.float
madmom/features/tempo.py	np.float
madmom/audio/signal.py	np.float
madmom/audio/filters.py	np.float
madmom/utils/__init__.py	np.float, np.int

Patch Script

I've published a complete post-install patch script that fixes all 11 files:

Gist: https://gist.github.com/znatri/2f36c7925615a32d8c9a0b66935701b3

The script:

• Locates madmom via pip show (not import, which would crash before patching)
• Scans all .py files recursively
• Replaces np.float → np.float64 and np.int → np.int64 using regex negative lookahead (so np.float64, np.float32, etc. are untouched)
• Works cross-platform (macOS + Linux)

Usage

pip install Cython==3.0.10 setuptools numpy==1.26.4
pip install --no-build-isolation madmom==0.16.1
bash patch-madmom.sh

Additional Note: Build Isolation

madmom 0.16.1 also fails to build under pip's default PEP 517 build isolation because its setup.py requires Cython at compile time. The fix is to pre-install Cython and use --no-build-isolation:

pip install Cython==3.0.10 setuptools numpy==1.26.4
pip install --no-build-isolation madmom==0.16.1

Ideal Fix

A new PyPI release of madmom with these aliases updated would resolve this for everyone. PR #542 addresses this on the main branch but hasn't been released. Would it be possible to cut a 0.16.2 or 0.17 release?

Related

• the beat tracking rely on numpy=<1.19 #527 — Original report of this issue
• Replace deprecated NumPy types (np.int and np.float) with int and float #542 — PR fixing numpy aliases on main branch
• Installation fails #550 — Installation failure (related to Cython build isolation)