The productivity of tomorrow trumps that of today¶
That’s probably harsh, but I think it is absolutely right. Doing crappy software today to be more productive today will make you less productive tomorrow. It’s this simple. And that’s cumulative too; meaning that if you neglect your future productivity, it will be slowly diminishing until a point of negative competitive disadvantage where you’ll find yourself struggling to keep up instead of innovating.
And it’s so damn exhausting to explain why…
Software complexity does not come from the tools, but from the mental framework required (and imposed at times) to understand it. So don’t ever think measuring Cyclomatic Complexity (CC) and other similar metrics will yield something close to the true measure of the quality of your code.
There are only two hard things in Computer Science: cache invalidation and naming things.
—Phil Karlton
def _check(l):
if len(l) <= 1:
return l
l1, l2 = [], []
m = l[0]
for x in l[1:]:
if x <=m :
l1.append(x)
else:
l2.append(x)
return _check(l1) + [m] +_check(l2)
This code has a nice CC of 4 which is very nice; yet it will take you at least a minute to figure out what it does. If only I had chosen to name the function quicksort…
>>> _check([84, 95, 89, 4, 77, 24, 95, 86, 70, 16])
[4, 16, 24, 70, 77, 84, 86, 89, 95, 95]
A quiz in less than 5 seconds: What does it mean in OpenERP’s ORM the following lines of code?
group.write({'implied_ids': [(3, implied_group.id)]})
This line of code has a CC of 1: as good as it gets, isn’t it? But it’s so darn difficult to read that unless you have your brain wired up to see “forget the link between this group and the implied_group”… To be fair there is someone out there in the OpenERP universe that cared a bit about this:
# file addons/base/ir/ir_fields.py
CREATE = lambda values: (0, False, values)
UPDATE = lambda id, values: (1, id, values)
DELETE = lambda id: (2, id, False)
FORGET = lambda id: (3, id, False)
LINK_TO = lambda id: (4, id, False)
DELETE_ALL = lambda: (5, False, False)
REPLACE_WITH = lambda ids: (6, False, ids)
But no one else is using it!
And, yes, it’s exhausting going over this.