Thursday, May 29, 2008

White space

I came across an interesting blog post the other this morning: Python Indentation considered boneheaded I like meaningful indentation. Because I find it easier to think that way. I had coded in other languages for quite some time before discovering python.

This means that I have probably spent weeks of accumulated time going back and adding semicolons to statements because I forgot to terminate them the first time round.

As for using python on larger projects. Well the answer is internal standards. If you try to contribute to C projects like GTK they come out and say things about standards right up front.
If you submit a patch and it doesn't meet the coding standards then we are going to reject it out of hand. Its quite a reasonable position to take.

Moreover a good editor will support a whitespace delimited language. My examples are from vim, though I assume that Emacs can do similar things as well (no need for another editor flame war).
  • Auto indentation sticks consistent indents on my lines.
  • Editor can highlight lines that mix tabs and spaces in their indents.
  • Files can carry a special comment which defines indentation rules.
  • If all else fails you can switch to a mode where whitespace characters are rendered so they are visible.
In my day jobs all the code is python. The code base is quite large and has probably had over twenty developers working on it over the last nine years. For reasons which are lost to history we use tabs only in all the files, and it works. Some developers do seem to feel strongly about the tabs vs spaces debate. Before starting here I used spaces, but when it comes done to it I really don't have a preference. About the only Thing I will attest to is that you should not mix the two approaches in the one file.

I had to write some java a while back, only a small simple problem, and after python I found it unbelivably hard. I realise this is largely personal preference, but iit felt like the syntax was fighting against me rather than helping me.

At the end of the day a good syntax is one which you don't notice. Foe me being a visual person seeing well indented code gives me a quick graps of what the code is supposed to do. One of my egocentricities in this regard is that I prefer:

if foo:
# do something else
if foo:
# do something else
Python will behave the same way in both cases, however for me the first option is more explicit. as I can see that we have an else branch without having to reach the code. If the body of the if is long enough it could be easy to miss that pesky return statement.

No comments: