The vJoule API for python is accessible from the source repository of vJoule.

The installation is made using a local pip install.

git clone https://github.com/davidson-consulting/vjoule.git
cd vjoule/tools/api/py/src/
pip install .

Here is a simple example using the installed API.

from vjoule_api_py.vjoule_api import *

def computePi(prec):
    res = 0
    for i in range(prec):
        i_prec = 1.0 / prec
        res += (4.0 / prec) / (1.0 + ((i - 0.5) * i_prec) * ((i - 0.5) * i_prec))
    return res


api = VJouleAPI ()
m_beg = api.getCurrentMachineConsumption ()
    
pi = computePi (10000000)

m_end = api.getCurrentMachineConsumption ()

m_diff = m_end - m_beg

print ("PI : ", pi)
print (m_diff)

$ python main.py
PI :  3.1415928535904256
diff (time: 2.00s, pdu: 83.10J, cpu: 41.89J, ram1.56J, gpu: 0.30J)

The API is base on the type VJouleAPI. This type is used to retreive the consumption of the machine from different components (enabled by the configuration of the vjoule_service).

The Python API uses the vjoule service to retrieve the consumption of the components. The service must be running, using the simple core plugin. The getCurrentMachineConsumption function triggers a consumption reading by the service, and retrieves the values of each enabled component (disabled components are set to 0). So there is no need to wait for the next iteration of the service to read a value. In fact, the service can be configured with a frequency of 0 (i.e., no iteration at all).