Category Archives: Programming

Creating a time series from existing data in pandas

9 May 2017

pandas is a high-performance library for data analysis in Python. It’s generally excellent, but if you’re a beginner or you use it rarely, it can be tricky to find out how to do quite simple things — the code to do what you want is likely to be very clear once you work it out, […]

Parsing website SSL certificates in Python

9 December 2016

A kindly PythonAnywhere user dropped us a line today to point out that StartCom and WoSign’s SSL certificates are no longer going to be supported in Chrome, Firefox and Safari. I wanted to email all of our customers who were using certificates provided by those organisations. We have all of the domains we host stored […]

SHA-1 sunset in Chromium, and libnss3

6 August 2015

This post is a combination of a description of a Chrome bug (fixed in May), a mea culpa, and an explanation of of the way HTTPS certificates work. So there’s something for everyone! :-) Here’s the situation — don’t worry if you don’t understand all of this initially, a lot of it is explained later. […]

A fun bug

28 March 2014

While I’m plugging the memory leaks in my epoll-based C reverse proxy, I thought I might share an interesting bug we found today on PythonAnywhere. The following is the bug report I posted to our forums. So, here’s what was happening. Each web app someone has on PythonAnywhere runs on a backend server. We have […]

…just resting…

12 December 2013

Just a quick note to say that I’m still here! Using rsp as a front-end for this site has usefully shown up some weird bugs, and I’m tracking them down. I’ll do a new post about it when there’s something useful to say…

A brief sidetrack: Varnish

2 October 2013

In order to use this blog as a decent real-world test of rsp, I figured that I should make it as fast as possible. The quickest way to do that was to install Varnish, which is essentially a reverse proxy that caches stuff. You configure it to say what is cachable, and then it runs […]