Implementing a Standard Library

Components

I use the following for building up utility scripts.

$ ls -lR ~/lib/py

/home/pharding/lib/py:
total 4
drwxr-xr-x+ 1 pharding Users 0 Feb 20 11:44 performiq

./performiq:
total 7
-rw-r--r-- 1 pharding Users  108 Feb 20 11:06 __init__.py
-rw-r--r-- 1 pharding Users   23 Feb 20 10:52 CONSTANTS.py
-rw-r--r-- 1 pharding Users  361 Feb 20 10:55 Enum.py
-rw-r--r-- 1 pharding Users 2121 Feb 20 11:32 Logger.py
-rw-r--r-- 1 pharding Users 2121 Feb 20 11:32 Timer.py

env | grep PYTHONPATH

PYTHONPATH=/home/pharding/lib/py

__init__.py

$ cat __init__.py

import CONSTANTS

from CONSTANTS import VERSION
from Enum      import Enum
from Logger    import Logger
from Timer     import Timer

CONSTANTS.py

$ cat CONSTANTS.py

VERSION   = "1.0.0"

Enum.py

$ cat Enum.py

#==========================================================================

class Enum(set):
   pass

   #--------------------------------------------------------------------

   def __getattr__(self, name):
      if name in self:
         return name
      raise AttributeError

#==========================================================================

Logger.py

$ cat Logger.py

import os
import sys
import logging

#==========================================================================

class Logger:
    logger = None
    debug  = False

    @classmethod
    def Info(cls, msg):
        global debug_level, verbose_flg

        if not cls.logger:
            cls.Init()

        cls.logger.info(' ' + msg)

        if cls.debug: sys.stderr.write("[%s::INFO]  %s\n" % (cls.name, msg))

    #----------------------------------------------------------------------

    @classmethod
    def Error(cls, msg):
        global debug_level, verbose_flg

        if not cls.logger:
            cls.Init()

        cls.logger.error(msg)

        if cls.debug: sys.stderr.write("[%s::ERROR]  %s\n" % (cls.name, msg))

    #----------------------------------------------------------------------

    @classmethod
    def Warning(cls, msg):
        global debug_level, verbose_flg

        if not cls.logger:
            cls.Init()

        cls.logger.warning('*****' + msg + '*****')

        if cls.debug: sys.stderr.write("[%s::WARNING]  %s\n" % (cls.name, msg))

    #----------------------------------------------------------------------

    @classmethod
    def Init(cls, name='logger', log_dir='/c/temp', debug=False):
        cls.debug = debug
        cls.name  = name
        cls.pid   = os.getpid()

        if cls.debug: sys.stderr.write("[%s::Init] PID is %d\n" % (cls.name, cls.pid))

        cls.log_file = '%s/%s.log' % (log_dir, name)

        try:
            cls.logger  = logging.getLogger(name)
            cls.hdlr    = logging.FileHandler(cls.log_file)
            cls.fmtr    = logging.Formatter('%(asctime)s %(levelname)s %(message)s')

            cls.hdlr.setFormatter(cls.fmtr)
            cls.logger.addHandler(cls.hdlr)
            cls.logger.setLevel(logging.INFO)

            cls.logger.info("===== Started processing %s" % ('=' * 20))
 
            cls.count = 0
        except IOError, msg:
            sys.stderr.write(cls.log_file + ': cannot open: ' + `msg` + '\n')
            sys.exit(1)

#==========================================================================

Timer.py

#==========================================================================

class Timer:
    t_reference = None

    #----------------------------------------------------------------------

    @classmethod
    def init(cls):
       return float(cls.get_reference_time(init=True)) * 0.001

    #----------------------------------------------------------------------

    @classmethod
    def time(cls):
       return float(cls.get_reference_time()) * 0.001

    #----------------------------------------------------------------------

    @classmethod
    def get_reference_time(cls, init=False):
       t_now  = datetime.now()

       if (flg):
          cls.t_reference   = t_now
          t             = 0
       else:
          t_delta       = t_now - cls.t_reference
          t             = ((t_delta.seconds * 1000000) + t_delta.microseconds)/1000.0

       return t

    #----------------------------------------------------------------------

#==========================================================================

A Test Harness

Use this to test the performiq module...

$ cat tst_module.py 
#!/usr/bin/env python

import time

import performiq

from performiq import Logger

debug_level  = 0
verbose_flg  = True


print "performiq version [%s]" % performiq.VERSION


print "Set timer - %5.3f" % performiq.Timer.init()

Logger.Init(debug=True)

Logger.Info("Testing - Info...")
Logger.Warning("Testing - Warning...")
Logger.Error("Testing - Error...")

time.sleep(3)

print "Get timer - %5.3f" % performiq.Timer.time()

Running it:

$ ./tst_module.py 
performiq version [1.0.0]
Set timer - 0.000
[logger::Init] PID is 8404
[logger::INFO]  Testing - Info...
[logger::WARNING]  Testing - Warning...
[logger::ERROR]  Testing - Error...
Get timer - 3.001

A Variant skel.py

This variant of my skel.py script uses the module.