##// END OF EJS Templates
added py4science demos as examples + NetworkX DAG dependencies
added py4science demos as examples + NetworkX DAG dependencies

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example-embed.py
131 lines | 4.4 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.core.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.\n'
'Note that if you use %kill_embedded, you can fully deactivate\n'
'This embedded instance so it will never turn on again')
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> ***********************