Python Time 2025
A quick reference for time...
from datetime import datetime, UTC
datetime.now(UTC)
datetime.datetime(2025, 1, 28, 23, 4, 45, 419714, tzinfo=datetime.timezone.utc)
You might think you should use datetime.utcnow() but:
Deprecated since version 3.12: Use
datetime.now()with …
SQLAlchemy Cascade Delete: Clarity through Examples
Since there is overlapping "cascade delete" functionality supported by SQLAlchemy -- with the ORM handling some deletes and the database itself handling others -- it can be hard to know the right way to set it up. Here are some examples to help clarify how it all works.
Here we …
Public Key Cryptography Made Easy
Learning about cryptography can be discouraging. You get so bombarded by "don't invent your own", "you're doing it wrong", and "even really smart people screw this up" that you wonder why you even bother to try. For me, the answer is because if you don't learn it, someone who knows …
SQLAlchemy with Python 64-bit on Windows
While hooking up SQLAlchemy for a web project, I kept running into attribute errors for 'session_registry'. I figured I was doing something wrong, so I thought I'd just walk through the tutorial as a sanity check.
I was, apparently, insane.
>>> u = session.query(User).filter_by(name='ed').first()
Traceback (most …Python Packaging (2013 Edition)
About a year ago, I set out to get a solid working understanding of Python packaging, resulting in a lengthy blog post of what I learned. There have been some significant course changes over that year such that my original post is wrong in several regards.
Here's a summary of …
Python Packaging Demystified
IMPORTANT: Some of the information in this post is now obsolete. Please see here.
Randomly take a couple of words from the following list, put them together, and there's a decent chance you'll come up with something real involving Python packaging.
The …
MessageBox: Just Say Nein
The Windows MessageBox is really convenient to use. A single line of code gets you a dialog box with a caption, a message, an icon and a set of available buttons that cover a lot of possible input scenarios. Unfortunately, the text on the buttons is supplied by the system …
.NET Color Struct Equality
When is white not white? When one is Color.White and the other is
Color.FromArgb(0xff, 0xff, 0xff, 0xff).
I was trying to data bind a list of colors to a ComboBox and
have the SelectedValue property bound to a particular color. The
frustrating thing was that even though …
.NET Cold Startup Performance: More
A few months ago I wrote about an approach to improving .NET cold startup performance. Here's a little more information that I've learned since then.
Another useful tool for optimizing cold startup is Microsoft's free CLR Profiler 2.0. While this tool has the aesthetics of a wadded-up paper sack …
Corrupt docx File After Adding Custom Properties Part
I spent a few days implementing a component that adds some custom properties to Office 2007 files. Using the System.IO.Packaging namespace from .NET 3.0, and looking at some sample code in some Visual Studio snippets, things went pretty smoothly. Just when I thought I was done, though …