matplotlib-devel Mailing List for matplotlib

>>>>> "Steve" == Steve Chaplin <ste...@ya...> writes:
 Steve> I suggest - for optional modules (like dates), only import
 Steve> them when they are required (when the plot actually has a
 Steve> date) - for all modules try to minimise the amount of code
 Steve> that will execute upon import, especially function calls.
 Steve> What do you think?
Sounds great. Thanks for tracking this one down. A 10% speedup is
well worth it. It sounds like the dates module should also cache the
timezone info. Do you want to take the lead on this one? 
JDH

I've been doing some profiling using
'hotshotmain.py simple_plot.py -dAgg >/tmp/hs-out 2>&1'
(with the Tools/scripts/hotshotmain.py script from the Python src
distribution)
I looked at the output and noticed that the pytz module takes up a fair
amount of the time. Which is a bit unexpected for simple_plot.py which
does not have any dates!
I commented out the 'dates' imports in pylab.py and axes.py and
performance increased 13%. It seemed strange for an import to have such
a large effect, but when I looked at dates.py I saw that it executes
code - it calls timezone() 9 times - a function which does further
imports which read in a lot of data.
If I restore the 'dates' imports and just comment out the 9 timezone()
calls in dates.py the speedup is 11% and it saves around 3,000 function
calls!
I suggest
- for optional modules (like dates), only import them when they are
required (when the plot actually has a date)
- for all modules try to minimise the amount of code that will execute
upon import, especially function calls.
What do you think?
Steve