/PyPnPObjects

This is a simple python module to get the Win32_WMIPnPEntity objects.

Primary LanguagePythonMIT LicenseMIT

PyPnPObjects

Table of content

Introduction

This is a simple python module to get the detail level information about Win32 WMI objects. To know more about Win32 PnpEntity, click on it.

Version Information

Current version of this module is in BETA version 0.1.9.

Installation

Installing pypnpobjects is as easy as installing any other python module.

Install with pip

pip install pypnpobjects

Install with git

git clone https://github.com/antaripchatterjee/PyPnPObjects.git
cd PyPnPObjects
python setup.py install

Uninstallation

You can uninstall this module whenever you want, using below method.

Uninstall using pip

pip uninstall pypnpobjects

Clearing

You can clear the folders and files created, during last installation using below command.

python clear.py

Platform Supports

PyPnPObjects is available only for win32 systems. I tested this module with python version 2.7.18 and python 3.5.4+, successfully.

*P.S.: When I tested this module with python 2, I could not use argument timeout of WMIStorePNPObjects.load method, and in windows 7, some properties of pnp entity was missing (e.g. PNPClass).

Dependencies

There are no such external dependencies, except it uses windows powershell.

Usage

You can either use this module as a CLI application or you can also use it in your python script.

CLI

You can run a simple command as below to test it's functionality.

get-pnpobjects -select name -select pnpclass -where pnpclass:audio% -ignore_case -operator like

When I executed the above command it gave the below output, it might be different in your system.

Name                    :Microphone (Realtek(R) Audio)
PNPClass                        :AudioEndpoint

Name                    :Speakers (Realtek(R) Audio)
PNPClass                        :AudioEndpoint

Name                    :Stereo Mix (Realtek(R) Audio)
PNPClass                        :AudioEndpoint

To get the version, you can use below command.

get-pnpobjects -version

You can also get the metadata about the project by using below command.

get-pnpobjects -meta <Meta-Property>

To know about the available meta properties, use -show-meta-props.

get-pnpobjects -show-meta-props

You can use -h to know more.

get-pnpobjects -h

Python script

Just do copy and paste to test this code.

from pypnpobjects import WMIStorePNPObjects

if __name__ == "__main__":
    with WMIStorePNPObjects() as wmipnp:
        proc_res = wmipnp.load()
        if proc_res[0] == 0:
            for dev in wmipnp.query('*', pnpclass='cameR_', case_sensitive_comparision = False, comparision_operator = 'like'):
                print('Device %s is %s'%(dev.Name))
        else:
            print('Error with code %d : %s'%(proc_res))

For me the output was as below, since I am only having integrated camera in my computer.

Device Name is USB2.0 VGA UVC WebCam

API References

The primary class of this module is WMIStorePNPObjects, however it also includes some other classes for internal purpose which are WMIStorePNPObjectsException and WMIInternalPNPObjectProperties.

WMIStorePNPObjects(object)

This class contains some public methods and they are load, query and free. This class is also having some implementations of __enter__ and __exit__ magic methods which means it supports context manager functionality as well, so that you do not need to explicitly free and close the context.

Constructor

The __init__ method takes a single positional argument which expects a value of list or str type object.

(optional) str | list | tuple command: The default value of this argument is ["Get-WmiObject", "Win32_PnPEntity"] but you can also change the value according to your need. The argument value should be a valid powershell command too.

If you run the below powershell command you will get an overall idea about the available properties for different kind of PnP entities.

Get-WmiObject Win32_PnpEntity

Representation

This class also implements the __repr__ magic method which also let us see the powershell command, that will be executed after calling the load method. You can refer the below code.

from pypnpobjects import WMIStorePNPObjects

if __name__ == "__main__":
    with WMIStorePNPObjects() as wmipnp:
        print(wmipnp)
        ...
        ...

The above code will generate a output like below.

WMIStorePNPObjects object at 0x216ffb969b0 <powershell Get-WmiObject Win32_PnPEntity>
...
...

def load(self, ...) -> tuple

A very important method from this class is load, which does a number of sequential tasks like, it first executes the command if the command is valid, then parses the command result and creates a python dict and finally stores the result into a SQLite database instance. It also takes a number of positional arguments and below you will find some useful information about them.

(optional) str db: The value for this argument should be either ':memory:' or ':file:'. The default value is ':memory:' and the SQLite database will be created in memory but not as a physical file and hence this option is making the database volatile. If you choose it as ':file:', then a physical SQLite file, called win32_pnpentity.sqlite.db, will be created in the same working directory and you can also reuse it later in your application. Any value other than ':memory:' or ':file:' will be changed to ':memory:'.

(optional) str table: The value of this argument refers the table name of the SQLite database where all the information about the PnP entities will be stored. The default value is Win32_PnPEntity.

(optional) int expected_exit_code: The default value for this argument is 0 and the load method returns immediately if the exit code of the command or process is not same as expected_exit_code.

(optional) int timeout: The value of this argument is time in second to find and execute the command or process. The default value is 30. To study more about this option refer this link from subprocess module. If the time limit exceeds, the load method will return immediately with return code as None and with a error message. This argument is only available for python 3.

This method returns an object of tuple of length 2. The 0th element, which is a int type object, is the exit code of the command or process and the 1st element, which is a str type object, holds the error message if any error occurred during the execution.

def query(self, ...) -> types.GeneratorType

Another important public method is query which basically queries the required information based on your input to the function from the same SQLite database connection. It also takes number arguments as input.

(optional) str | int *select: This is a variable length non-keyword argument. Each value in this argument either should be a valid property name or a valid property index otherwise it will throw a WMIStorePNPObjectsException. If you keep it empty while calling the method, the query method itself will fetch all the properties for an entity from the same SQLite database instance.

(optional) str | int | float | bool **where: This argument is a variable length keyword argument, which takes any valid property id of an entity as a keyword and the value of the keyword is used as a where condition during the query execution. The value can also be a SQL pattern and this can be matched with SQL operator LIKE.

(optional) str comparision_operator: This argument should be either 'like' or 'equal' and the default value is 'equal' which means the query method will do a equality check while querying the entities but if we specify 'like', the method will use SQL operator LIKE to match the pattern instead. Any value other than 'like' or 'equal' will be changed to 'equal'.

(optional) bool | int | str case_sensitive_comparision: This argument should receive a python bool object i.e. either it should be True or False but if we specify any non-zero values, it would be considered as True otherwise False. Also we can pass str representation of True or False. The default value is True which means, the conditions will be checked as case sensitively otherwise it will be checked as case insensitively.

This method returns a generator object and each element of it is a object of WMIInternalPNPObjectProperties, which holds the data about the properties of a PnP entity, and you can see them either by using key-value mechanism (e.g dev['Name']) or by using . operator (e.g. dev.Name) and this keys are case insenitive which means dev.name == dev.Name will give you True result and every property returns a tuple of actual property id and it's value i.e. dev.name will return ('Name', '<Property Value>').

def free(self) -> NoneType

This method closes the connection of the same SQLite database instance and does not return any value, however if you use with context manager, you do not need to explicitly call this method.

WMIStorePNPObjectsException(Exception)

This class is a exception type and it is used internally to raise different concerns during the execution.

WMIInternalPNPObjectProperties(object)

Every element of the generator object, returned by WMIStorePNPObjects.query method, is a object of WMIInternalPNPObjectProperties class. This class is having some ground level implementations of __contains__, __getattr__, __getitem__, __iter__ and __len__ magic methods, in order to provide some dict like functionalities however this class is inherited from object class only.

Development Areas

I was working in a project which had some requirements and I could not figure out the solutions for them, so I have made this python module, however I have more plans to implement in it and will update them on a regular basis. Below are some points, which I am planning to implement.

  • I will make a similar python module for *NIX based system to make it cross-platform.
  • I will also make this module compatible for any WINDOWS system which does not have powershell.

License

With the power of opensource project, this module is licensed with MIT License which let you feel free to do any thing that comes under MIT License.

Contribution

Pull requests are always awesome and you are free to contribute anytime, but please make sure to raise a ticket before doing any changes.