You need to worry about deployment
Posted by Jason Baker on April 29, 2009
Oftentimes, people used to using PHP or Classic ASP will give up on Python because deploying Python scripts isn’t just a simple matter of copying and pasting files. Usually, this isn’t because Python is making their lives difficult. It’s more a matter of not thinking about how to deploy your scripts ahead of time.
Now, I’m far from a highly experience programmer, but I can tell you one thing. Deployment is a detail that will come back to bite you if you don’t spend a little bit of time on it up front. So here are a few pointers I’ve come up with after experiences in deploying Python scripts for web apps.
- Batch/Shell scripts are your friends. A common objection is that a person just doesn’t have time to learn a new tool for deploying. I have two responses to this: 1) Drop that attitude otherwise you’ll never get anywhere as a programmer and 2) Don’t use them if you really don’t want to! While batch and shell scripts aren’t the prettiest options, they’re a lot better than having nothing to automate deployment at all. In fact, for the basic one or two page webapp, you can’t really do much better.
- If you invest some time in Continuous Integration, you won’t regret it. I know what you’re saying. Continuous Integration is a Java thing. It’s too complicated. And you’d be right to a point. However, I would argue that making sense of the complication is worth your time. It’s way too easy to deploy something that doesn’t work because somebody forgot to run their unit tests.
- Site-wide packages are evil. If you aren’t already, you should really be taking advantage of virtualenv. That is, unless of course you enjoy troubleshooting weird ImportErrors because of that egg you installed using the setuptools develop command a month ago and forgot to remove.
- Don’t underestimate the value of good docs. Having good documentation is just one of those things that don’t become obviously necessary until it’s too late. Don’t leave yourself trying to figure out how that one function you wrote a year ago works. Write documentation as you go and use a tool like sphinx to turn it into a webpage. This ties in with point 2. Using Continuous Integration will make doc generation that much easier.
Admittedly, doing this stuff can be a pain. And you might get scorn from co-workers for not having something ready the next day. But it will be worth it. You’ll be surprised at how much time you’ll save in the long run.