Question

Where is ipython’s configuration file, which starts with c = get_config(), executed? I’m asking because I want to understand what order things are done in ipython, e.g. why certain commands will not work if included as c.InteractiveShellApp.exec_lines.

This is related to my other question, Log IPython output?, because I want access to a logger attribute, but I can’t figure out how to access it in the configuration file, and by the time exec_lines are run, the logger has already started (it’s too late).

EDIT: I’ve accepted a solution based on using a startup file in ipython0.12+. Here is my implementation of that solution:

from time import strftime
import os.path

ip = get_ipython()

#ldir = ip.profile_dir.log_dir 
ldir = os.getcwd()
fname = 'ipython_log_' + strftime('%Y-%m-%d') + ".py"
filename = os.path.join(ldir, fname)
notnew = os.path.exists(filename)


try:
  ip.magic('logstart -o %s append' % filename)
  if notnew:
      ip.logger.log_write( u"########################################################\n" ) 
  else:
      ip.logger.log_write( u"#!/usr/bin/env python\n" )
      ip.logger.log_write( u"# " + fname + "\n" )
      ip.logger.log_write( u"# IPython automatic logging file\n" )
  ip.logger.log_write( u"# " + '# Started Logging At: '+ strftime('%Y-%m-%d %H:%M:%S\n') ) 
  ip.logger.log_write( u"########################################################\n" ) 
  print " Logging to "+filename
except RuntimeError:
    print " Already logging to "+ip.logger.logfname

There are only two subtle differences from the proposed solution linked:
1. saves log to cwd instead of some log directory (though I like that more…)
2. ip.magic_logstart doesn’t seem to exist, instead one should use ip.magic('logstart')

Answer 1

The config system sets up a special namespace containing the get_config() function, runs the config file, and collects the values to apply them to the objects as they’re created. Referring to your previous question, it doesn’t look like there’s a configuration value for logging output. You may want to start logging yourself after config, when you can control it more precisely. See this example of starting logging automatically.

Your other question mentions that you’re limited to 0.10.2 on one system: that has a completely different config system that won’t even look at the same file.