python#

SQLAlchemy mixin in method

If I'm not wrong, the SQLAlchemy official doc provides some examples to explain how to share a set of common columns, some common table options, or other mapped properties, across many classes. But I cannot find how to share common methods (e.g. your customized to_dict() method). This post will just show you a POC to achieve this goal by using Python Mixin.

Troubleshooting Python Twine Cannot Upload Package On Windows

Python has several tools to upload packages to PyPi or some private Artifactory locations. The mostly used one should be twine. Although twine is not a Python originate tool, but it's officially recommended by Python.org.

Filtering In Pandas Dataframe

Pandas dataframe is like a small database, we can use it to inject some data and do some in-memory filtering without any external SQL. This post is much like a summary of this StackOverflow thread.

Using Python SQLAlchemy session in concurrent threads or tasks

SQLAlchemy DB session is not thread safe for both sync and async session. AsyncSession is only a thin proxy on top of a Session

The concurrency model for SQLAlchemy's Session and AsyncSession is therefore Session per thread, AsyncSession per task.

The best way to ensure this use is by using the standard context manager pattern locally within the top level Python function that is inside the thread or task, which will ensure the lifespan of the Session or AsyncSession is maintained within a local scope.

For applications that benefit from having a "global" Session where it's not an option to pass the Session object to specific functions and methods which require it, the scoped_session approach can provide for a "thread local" Session object; see the section Contextual/Thread-local Sessions for background. Within the asyncio context, the async_scoped_session object is the asyncio analogue for scoped_session, however is more challenging to configure as it requires a custom "context" function.

Creating Custom Python Request Auth Class

When you need to use a complicated, or a non-standard API authentication method, or your dev and prd environments don't use the same API authentication method, it might be better to create a Python requests auth method to reduce your work.

Using Gitlab integrated CICD for Python project on Windows

Gitlab ships with its own free CICD which works pretty well. This post will give you an example of the CICD file .gitlab-ci.yml for a Python project running on Gitlab Windows runner.

Use python tabulate module to create tables

If you want to create some tables from a python list, you can use the tabulate module, it can generate the table easily in text mode and in many formats, than you can past it into markdown, wiki files or add the print version to your python CLI in order to give a beautiful output to the CLI users.

Use pyVmomi EventHistoryCollector to get all the vCenter events

pyVmomi eventManager's QueryEvents() method returns by default only the last 1000 events occurred on the vCenter. I will show you how to use another method CreateCollectorForEvents() to create an EventHistoryCollector object and then we use this object to collect all the events in a given time range by using its method ReadNextEvents().

Install Python on Windows with Powershell without administrator privileges

As a Windows DevOps, I often use Powershell and Python, Powershell is installed by Windows out of box, but this is not for Python. And for my working environment, I don't have the administrator privileges on some servers. I will show you in this post how to rapidly deploy Python on Windows as a standard user by using Powershell with Nuget.

Import Python module with sys.path variable when without __init__ file

We're familiar to put a python file inside a folder, and create a __init__.py file under the same folder, then we can easily import the file by import the folder, as the folder is transformed to a python module. But if we don't have the __init__.py, how can we import it?