[mod_python] Graphs in a webpage

Alexis Iglauer aiglauer at yahoo.com
Tue Nov 14 02:45:56 EST 2000

First of all, thank you to everyone for the pointers.
> I used gd with nsapy on a windows machine in 1997

Will check it out, thanks....

> The things that are the slowest are repetetive
> operations that involve
> memory allocations - e.g. if you're building some
> large list from the
> ascii files one byte at a time and your ascii file
> is 90K, it will be
> slow. You will see a big improvement if you only
> build the list once and
> cache it inside a module somewhere. 

I am using the following construct often:

i = open (datafile)
l = i.readlines()

on 200KB+ files - looks like that could be the problem
:)  Is it more efficient to loop using

for l in i.readlines():      ?

My datafiles are time series data, usually for 24
hours at a time, so I will have a whole bunch of
datafiles which make up a contiguous set of data over
several days/months/years.  The last datafile will
probably always be growing.  A two-stage caching
module may do the trick.

> If your content is dynamic and cannot be cached,
> then try to avoid things
> like readlines() of the whole file, then copying it
> some list. A much
> faster solution is to read the file as you need the
> data avoiding all
> unnecessary mallocs.

This seems to answer my question above in the
positive.  I will however still be reading all my
datafiles every time.

> Python "import" mechanism - make a module that reads
> all your ascii files,
> then import it from a script. Python only imports
> once the first time and
> ignores all subsequent requests - perfect for
> caching.

Does "first time" here mean the first time apache is
started or the first time an apache process is


Yup, thanks

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