##// END OF EJS Templates
Install signal handler on each code run to protect against user code that...
Install signal handler on each code run to protect against user code that may modify it as well. If we don't do this, on the next Ctrl-C python itself will likely just crash completely.

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example-embed.py
129 lines | 4.2 KiB | text/x-python | PythonLexer
#!/usr/bin/env python
"""An example of how to embed an IPython shell into a running program.
Please see the documentation in the IPython.Shell module for more details.
The accompanying file example-embed-short.py has quick code fragments for
embedding which you can cut and paste in your code once you understand how
things work.
The code in this file is deliberately extra-verbose, meant for learning."""
# The basics to get you going:
# IPython sets the __IPYTHON__ variable so you can know if you have nested
# copies running.
# Try running this code both at the command line and from inside IPython (with
# %run example-embed.py)
try:
__IPYTHON__
except NameError:
nested = 0
args = ['']
else:
print "Running nested copies of IPython."
print "The prompts for the nested copy have been modified"
nested = 1
# what the embedded instance will see as sys.argv:
args = ['-pi1','In <\\#>: ','-pi2',' .\\D.: ',
'-po','Out<\\#>: ','-nosep']
# First import the embeddable shell class
from IPython.Shell import IPShellEmbed
# Now create an instance of the embeddable shell. The first argument is a
# string with options exactly as you would type them if you were starting
# IPython at the system command line. Any parameters you want to define for
# configuration can thus be specified here.
ipshell = IPShellEmbed(args,
banner = 'Dropping into IPython',
exit_msg = 'Leaving Interpreter, back to program.')
# Make a second instance, you can have as many as you want.
if nested:
args[1] = 'In2<\\#>'
else:
args = ['-pi1','In2<\\#>: ','-pi2',' .\\D.: ',
'-po','Out<\\#>: ','-nosep']
ipshell2 = IPShellEmbed(args,banner = 'Second IPython instance.')
print '\nHello. This is printed from the main controller program.\n'
# You can then call ipshell() anywhere you need it (with an optional
# message):
ipshell('***Called from top level. '
'Hit Ctrl-D to exit interpreter and continue program.')
print '\nBack in caller program, moving along...\n'
#---------------------------------------------------------------------------
# More details:
# IPShellEmbed instances don't print the standard system banner and
# messages. The IPython banner (which actually may contain initialization
# messages) is available as <instance>.IP.BANNER in case you want it.
# IPShellEmbed instances print the following information everytime they
# start:
# - A global startup banner.
# - A call-specific header string, which you can use to indicate where in the
# execution flow the shell is starting.
# They also print an exit message every time they exit.
# Both the startup banner and the exit message default to None, and can be set
# either at the instance constructor or at any other time with the
# set_banner() and set_exit_msg() methods.
# The shell instance can be also put in 'dummy' mode globally or on a per-call
# basis. This gives you fine control for debugging without having to change
# code all over the place.
# The code below illustrates all this.
# This is how the global banner and exit_msg can be reset at any point
ipshell.set_banner('Entering interpreter - New Banner')
ipshell.set_exit_msg('Leaving interpreter - New exit_msg')
def foo(m):
s = 'spam'
ipshell('***In foo(). Try @whos, or print s or m:')
print 'foo says m = ',m
def bar(n):
s = 'eggs'
ipshell('***In bar(). Try @whos, or print s or n:')
print 'bar says n = ',n
# Some calls to the above functions which will trigger IPython:
print 'Main program calling foo("eggs")\n'
foo('eggs')
# The shell can be put in 'dummy' mode where calls to it silently return. This
# allows you, for example, to globally turn off debugging for a program with a
# single call.
ipshell.set_dummy_mode(1)
print '\nTrying to call IPython which is now "dummy":'
ipshell()
print 'Nothing happened...'
# The global 'dummy' mode can still be overridden for a single call
print '\nOverriding dummy mode manually:'
ipshell(dummy=0)
# Reactivate the IPython shell
ipshell.set_dummy_mode(0)
print 'You can even have multiple embedded instances:'
ipshell2()
print '\nMain program calling bar("spam")\n'
bar('spam')
print 'Main program finished. Bye!'
#********************** End of file <example-embed.py> ***********************