Posted on Mon, 29 Jan 2018 in Python • Tagged with typing, mypy, python
Type hints could help you a lot with a big Python project. However, they sometimes require code refactoring. I wrote about it last year in this article, but I have found a good example for this only now.
Posted on Mon, 11 Dec 2017 in Python • Tagged with typing, mypy, python
Many times I wrote that type hints in Python help to work with big or moderate projects. However, if you decide to add them to your project, you have to check your project regularly using CI. And this kind of checks is not easy to implement. This article is my story about obstacles in this process.
I'm trying to add type hints to our project for a while. And now I have a bunch of methods how to do it more efficiently, fast, and painless. I spend many days trying to find them. Now I want to share my experience.
asyncio is a useful library. However, it is not so easy to understand how to work with it. Documentation isn't enough. We need more examples. We need more explanations. The last couple of weekends I spent experimenting with this library. After that, I add some interesting articles into my Pocket. Here are some of them.
Python is a very flexible programming language. Its dynamic nature allows programmers to code elegant solutions that almost impossible to make with other more strict languages, for example, Java. However, you have to pay for everything. While Python code base grows, it requires more and more efforts to keep project integrity. Without these extra efforts, the project will fall apart.
Posted on Mon, 11 Sep 2017 in Python • Tagged with python, cpython
A couple of weeks ago one of my colleagues ask if Python function is possible to use as a key in dicts? Yes, it is. So, every function has a hash. But how is it calculated? Based on function name? Based on function byte code? Actually, it calculates by transforming a pointer to a function object. However, it is not so easy to find it in the CPython code.
Posted on Tue, 30 May 2017 in Python • Tagged with python, property
It looks obvious that you can override the property in a child class, and call "super" within it. Sounds OK? Yes, it is. However, when my colleague asked me about this behavior, I was confused. Maybe because I am a bit suspicious, every time I saw a magic thing of any kind in a code I expect a trap. What's why I decided to write a simple example to prove myself that it works as it should.
Posted on Fri, 19 May 2017 in Python • Tagged with python, pyenv
It can be painful to manage several Python versions on one laptop. However, it is a very common situation. Usually, developers have many projects that require different Python versions. There are a couple of variants to deal with it. My favourite is pyenv with virtualenv plugin. I used to use Homebrew itself to do that, but it wasn't so flexible.
Posted on Fri, 17 Feb 2017 in Python • Tagged with enums, python
Enums are less used feature in Python. We as programmers prefer to use weird dicts or lists where enum should be used. Why? Because it is rather new feature and you have to install back port library if you use Python 2.7. However, it's better to use them in many cases.
Posted on Wed, 23 Nov 2016 in Python • Tagged with python, java
Sometimes using None makes a mess of a code. For example, if you want to separate some "empty" value and "no data" value for integer input where 0 isn't "empty" value, it's very hard to do with None only. Possible solution is to use something like Optional in Java.
Posted on Thu, 03 Nov 2016 in Python • Tagged with python, backtracking, recursion
As you know there is no tail recursion optimization in Python. Moreover it has a very low recursion limit. It can be a problem if you are trying to solve the problem using the backtracking algorithm. Recursion limit is big enough to solve sudoku, but an exception will raise if the problem has more possible solutions.