>>> hou.Matrix3([[1,2,3],[4,5,6],[7,8,9]]).inverted()

Traceback (most recent call last):
  File "<console>", line 1, in <module>
  File "/opt/hfs17.0.497/houdini/python2.7libs/hou.py", line 39294, in inverted
    return _hou.Matrix3_inverted(*args)
OperationFailed: The attempted operation failed.

matrix3 matA = { {1,2,3}, {4,5,6}, {7,8,9} };

// Find the determinant of the matrix
// If the determinant value is zero, then an inverted matrix cannot be found for such a matrix.

int det = determinant(matA); // det == 0

matrix3 matB = invert(matA); // { {-0.75, 0.5, 0.25}, {-0.5, 0, -0.5}, {0.5833, 0.5, -0.083} }

import ctypes

def get_display_name():
    GetUserNameEx = ctypes.windll.secur32.GetUserNameExW
    NameDisplay = 3

    size = ctypes.pointer(ctypes.c_ulong(0))
    GetUserNameEx(NameDisplay, None, size)

    nameBuffer = ctypes.create_unicode_buffer(size.contents.value)
    GetUserNameEx(NameDisplay, nameBuffer, size)
    return nameBuffer.value

print get_display_name()

import subprocess

houdini_py = '%s\python27\python.exe' % hou.expandString("$HFS")
file_path = r'C:\get_display_name.py'
p = subprocess.Popen([houdini_py, file_path], stdout=subprocess.PIPE, shell=True)
print p.communicate()[0]

import re

string = "hou.Keyframe t=0.4 expr='bezier()' lang=exprLanguage.Hscript v=0 s=0 auto_slopes=True in a=0.133333 out a=0.333333 use_accel_ratio=True"
print re.search('\d{1,2}[\.]\d{1,2}', string).group()