Load opencv matrix in python ! reference from https://gist.github.com/autosquid/66acc22b3798b36aea0a

load_opencv_yaml.py

"""
reference from https://gist.github.com/autosquid/66acc22b3798b36aea0a

example yaml file:

%YAML:1.0
---
camera_matrix: !!opencv-matrix
   rows: 3
   cols: 3
   dt: d
   data: [ 4.8175329437169847e+02, 0., 3.0642034206715834e+02, 0.,
       4.8165811490603426e+02, 2.4021175432811785e+02, 0., 0., 1. ]
distortion_coefficients: !!opencv-matrix
   rows: 1
   cols: 5
   dt: d
   data: [ 5.0298513119414620e-02, -8.1903434648371942e-01,
       1.4316138220892072e-03, -1.3935294585502944e-02,
       1.0838184439911540e+00 ]
       
"""

import yaml # " $pip install pyyaml " if you haven't
import numpy as np

def _opencv_matrix(loader, node): # for constructor
    mapping = loader.construct_mapping(node, deep = True)
    mat = np.array(mapping["data"])
    mat = mat.copy()
    mat.resize(mapping["rows"], mapping["cols"])
    return mat
  
def load_opencv_yaml(file_name):
    skiplines = 2
    with open(file_name) as fin:
        for i in range(skiplines):
            _ = fin.readline()
        yaml.add_constructor(u"tag:yaml.org,2002:opencv-matrix", _opencv_matrix)
        result = yaml.load(fin)
    return result