_ip.load runs init_ipython even if the module already exists

IPython/ipapi.py

@@ -1,450 +1,457 b''
 ''' IPython customization API
 
 Your one-stop module for configuring & extending ipython
 
 The API will probably break when ipython 1.0 is released, but so 
 will the other configuration method (rc files).
 
 All names prefixed by underscores are for internal use, not part 
 of the public api.
 
 Below is an example that you can just put to a module and import from ipython. 
 
 A good practice is to install the config script below as e.g. 
 
 ~/.ipython/my_private_conf.py
 
 And do 
 
 import_mod my_private_conf 
 
 in ~/.ipython/ipythonrc
 
 That way the module is imported at startup and you can have all your
 personal configuration (as opposed to boilerplate ipythonrc-PROFILENAME 
 stuff) in there. 
 
 -----------------------------------------------
 import IPython.ipapi
 ip = IPython.ipapi.get()
 
 def ankka_f(self, arg):
     print "Ankka",self,"says uppercase:",arg.upper()
 
 ip.expose_magic("ankka",ankka_f)
 
 ip.magic('alias sayhi echo "Testing, hi ok"')
 ip.magic('alias helloworld echo "Hello world"')
 ip.system('pwd')
 
 ip.ex('import re')
 ip.ex("""
 def funcci(a,b):
     print a+b
 print funcci(3,4)
 """)
 ip.ex("funcci(348,9)")
 
 def jed_editor(self,filename, linenum=None):
     print "Calling my own editor, jed ... via hook!"
     import os
     if linenum is None: linenum = 0
     os.system('jed +%d %s' % (linenum, filename))
     print "exiting jed"
 
 ip.set_hook('editor',jed_editor)
 
 o = ip.options
 o.autocall = 2  # FULL autocall mode
 
 print "done!"
 '''
 
 # stdlib imports
 import __builtin__
 import sys
 
 # our own
 #from IPython.genutils import warn,error
  
 class TryNext(Exception):
     """Try next hook exception.
      
     Raise this in your hook function to indicate that the next hook handler
     should be used to handle the operation.  If you pass arguments to the
     constructor those arguments will be used by the next hook instead of the
     original ones.
     """
 
     def __init__(self, *args, **kwargs):
         self.args = args
         self.kwargs = kwargs
 
 class IPyAutocall:
     """ Instances of this class are always autocalled
     
     This happens regardless of 'autocall' variable state. Use this to
     develop macro-like mechanisms.
     """
     
     def set_ip(self,ip):
         """ Will be used to set _ip point to current ipython instance b/f call
         
         Override this method if you don't want this to happen.
         
         """
         self._ip = ip
     
 
 # contains the most recently instantiated IPApi
 
 class IPythonNotRunning:
     """Dummy do-nothing class.
 
     Instances of this class return a dummy attribute on all accesses, which
     can be called and warns.  This makes it easier to write scripts which use
     the ipapi.get() object for informational purposes to operate both with and
     without ipython.  Obviously code which uses the ipython object for
     computations will not work, but this allows a wider range of code to
     transparently work whether ipython is being used or not."""
 
     def __init__(self,warn=True):
         if warn:
             self.dummy = self._dummy_warn
         else:
             self.dummy = self._dummy_silent
     
     def __str__(self):
         return "<IPythonNotRunning>"
 
     __repr__ = __str__
 
     def __getattr__(self,name):
         return self.dummy
 
     def _dummy_warn(self,*args,**kw):
         """Dummy function, which doesn't do anything but warn."""
 
         print ("IPython is not running, this is a dummy no-op function")
 
     def _dummy_silent(self,*args,**kw):
         """Dummy function, which doesn't do anything and emits no warnings."""
         pass
 
 _recent = None
 
 
 def get(allow_dummy=False,dummy_warn=True):
     """Get an IPApi object.
 
     If allow_dummy is true, returns an instance of IPythonNotRunning 
     instead of None if not running under IPython.
 
     If dummy_warn is false, the dummy instance will be completely silent.
 
     Running this should be the first thing you do when writing extensions that
     can be imported as normal modules. You can then direct all the
     configuration operations against the returned object.
     """
     global _recent
     if allow_dummy and not _recent:
         _recent = IPythonNotRunning(dummy_warn)
     return _recent
 
 class IPApi:
     """ The actual API class for configuring IPython 
     
     You should do all of the IPython configuration by getting an IPApi object
     with IPython.ipapi.get() and using the attributes and methods of the
     returned object."""
     
     def __init__(self,ip):
         
         # All attributes exposed here are considered to be the public API of
         # IPython.  As needs dictate, some of these may be wrapped as
         # properties.
 
         self.magic = ip.ipmagic
         
         self.system = ip.system
         
         self.set_hook = ip.set_hook
         
         self.set_custom_exc = ip.set_custom_exc
 
         self.user_ns = ip.user_ns
 
         self.set_crash_handler = ip.set_crash_handler
 
         # Session-specific data store, which can be used to store
         # data that should persist through the ipython session.
         self.meta =  ip.meta
     
         # The ipython instance provided
         self.IP = ip
 
+        self.extensions = {}
         global _recent
         _recent = self
 
     # Use a property for some things which are added to the instance very
     # late.  I don't have time right now to disentangle the initialization
     # order issues, so a property lets us delay item extraction while
     # providing a normal attribute API.
     def get_db(self):
         """A handle to persistent dict-like database (a PickleShareDB object)"""
         return self.IP.db
 
     db = property(get_db,None,None,get_db.__doc__)
 
     def get_options(self):
         """All configurable variables."""
         
         # catch typos by disabling new attribute creation. If new attr creation
         # is in fact wanted (e.g. when exposing new options), do allow_new_attr(True) 
         # for the received rc struct.
         
         self.IP.rc.allow_new_attr(False)
         return self.IP.rc
 
     options = property(get_options,None,None,get_options.__doc__)
     
     def expose_magic(self,magicname, func):
         ''' Expose own function as magic function for ipython 
     
         def foo_impl(self,parameter_s=''):
             """My very own magic!. (Use docstrings, IPython reads them)."""
             print 'Magic function. Passed parameter is between < >: <'+parameter_s+'>'
             print 'The self object is:',self
     
         ipapi.expose_magic("foo",foo_impl)
         '''
                 
         import new
         im = new.instancemethod(func,self.IP, self.IP.__class__)
         setattr(self.IP, "magic_" + magicname, im)
     
     def ex(self,cmd):
         """ Execute a normal python statement in user namespace """
         exec cmd in self.user_ns
     
     def ev(self,expr):
         """ Evaluate python expression expr in user namespace 
         
         Returns the result of evaluation"""
         return eval(expr,self.user_ns)
     
     def runlines(self,lines):
         """ Run the specified lines in interpreter, honoring ipython directives.
         
         This allows %magic and !shell escape notations.
         
         Takes either all lines in one string or list of lines.
         """
         if isinstance(lines,basestring):
             self.IP.runlines(lines)
         else:
             self.IP.runlines('\n'.join(lines))
 
     def to_user_ns(self,vars, interactive = True):
         """Inject a group of variables into the IPython user namespace.
 
         Inputs:
 
          - vars: string with variable names separated by whitespace
 
          - interactive: if True (default), the var will be listed with
         %whos et. al.
          
         This utility routine is meant to ease interactive debugging work,
         where you want to easily propagate some internal variable in your code
         up to the interactive namespace for further exploration.
 
         When you run code via %run, globals in your script become visible at
         the interactive prompt, but this doesn't happen for locals inside your
         own functions and methods.  Yet when debugging, it is common to want
         to explore some internal variables further at the interactive propmt.
 
         Examples:
 
         To use this, you first must obtain a handle on the ipython object as
         indicated above, via:
 
         import IPython.ipapi
         ip = IPython.ipapi.get()
 
         Once this is done, inside a routine foo() where you want to expose
         variables x and y, you do the following:
 
         def foo():
             ...
             x = your_computation()
             y = something_else()
             
             # This pushes x and y to the interactive prompt immediately, even
             # if this routine crashes on the next line after:
             ip.to_user_ns('x y')
             ...
             # return           
         
         If you need to rename variables, just use ip.user_ns with dict
         and update:
         
         # exposes variables 'foo' as 'x' and 'bar' as 'y' in IPython 
         # user namespace
         ip.user_ns.update(dict(x=foo,y=bar))    
         """
 
         # print 'vars given:',vars # dbg
         # Get the caller's frame to evaluate the given names in
         cf = sys._getframe(1)
         
         user_ns = self.user_ns
         config_ns = self.IP.user_config_ns
         for name in vars.split():
             try:
                 val = eval(name,cf.f_globals,cf.f_locals)
                 user_ns[name] = val
                 if not interactive:
                     config_ns[name] = val
                 else:
                     config_ns.pop(name,None)
             except:
                 print ('could not get var. %s from %s' %
                 (name,cf.f_code.co_name))
 
     def expand_alias(self,line):
         """ Expand an alias in the command line 
         
         Returns the provided command line, possibly with the first word 
         (command) translated according to alias expansion rules.
         
         [ipython]|16> _ip.expand_aliases("np myfile.txt")
                  <16> 'q:/opt/np/notepad++.exe myfile.txt'
         """
         
         pre,fn,rest = self.IP.split_user_input(line)
         res = pre + self.IP.expand_aliases(fn,rest)
         return res
 
     def defalias(self, name, cmd):
         """ Define a new alias
         
         _ip.defalias('bb','bldmake bldfiles')
         
         Creates a new alias named 'bb' in ipython user namespace
         """
         
         
         nargs = cmd.count('%s')
         if nargs>0 and cmd.find('%l')>=0:
             raise Exception('The %s and %l specifiers are mutually exclusive '
                             'in alias definitions.')
                   
         else:  # all looks OK
             self.IP.alias_table[name] = (nargs,cmd)            
     
     def defmacro(self, *args):
         """ Define a new macro
     
         2 forms of calling:
         
         mac = _ip.defmacro('print "hello"\nprint "world"')
         
         (doesn't put the created macro on user namespace)
         
         _ip.defmacro('build', 'bldmake bldfiles\nabld build winscw udeb')
         
         (creates a macro named 'build' in user namespace)
         """
         
         import IPython.macro
         
         if len(args) == 1:
             return IPython.macro.Macro(args[0])
         elif len(args) == 2:
             self.user_ns[args[0]] = IPython.macro.Macro(args[1])
         else:
             return Exception("_ip.defmacro must be called with 1 or 2 arguments")
         
     def set_next_input(self, s):
         """ Sets the 'default' input string for the next command line.
         
         Requires readline.
         
         Example:
         
         [D:\ipython]|1> _ip.set_next_input("Hello Word")
         [D:\ipython]|2> Hello Word_  # cursor is here        
         """
 
         self.IP.rl_next_input = s
 
     def load(self, mod):
-        if mod in sys.modules:
-            return
+        if mod in self.extensions:
+            # just to make sure we don't init it twice
+            # note that if you 'load' a module that has already been
+            # imported, init_ipython gets run anyway
+            
+            return self.extensions[mod]
         __import__(mod)
         m = sys.modules[mod]
         if hasattr(m,'init_ipython'):
             m.init_ipython(self)
+        self.extensions[mod] = m
+        return m
         
 
 def launch_new_instance(user_ns = None):
     """ Make and start a new ipython instance.
     
     This can be called even without having an already initialized 
     ipython session running.
     
     This is also used as the egg entry point for the 'ipython' script.
     
     """
     ses = make_session(user_ns)
     ses.mainloop()
 
 
 def make_user_ns(user_ns = None):
     """Return a valid user interactive namespace.
 
     This builds a dict with the minimal information needed to operate as a
     valid IPython user namespace, which you can pass to the various embedding
     classes in ipython.
     """
 
     if user_ns is None:
         # Set __name__ to __main__ to better match the behavior of the
         # normal interpreter.
         user_ns = {'__name__'     :'__main__',
                    '__builtins__' : __builtin__,
                    }
     else:
         user_ns.setdefault('__name__','__main__')
         user_ns.setdefault('__builtins__',__builtin__)
 
     return user_ns
 
 
 def make_user_global_ns(ns = None):
     """Return a valid user global namespace.
 
     Similar to make_user_ns(), but global namespaces are really only needed in
     embedded applications, where there is a distinction between the user's
     interactive namespace and the global one where ipython is running."""
 
     if ns is None: ns = {}
     return ns
 
 
 def make_session(user_ns = None):
     """Makes, but does not launch an IPython session.
     
     Later on you can call obj.mainloop() on the returned object.
 
     Inputs:
 
       - user_ns(None): a dict to be used as the user's namespace with initial
       data.
     
     WARNING: This should *not* be run when a session exists already."""
 
     import IPython
     return IPython.Shell.start(user_ns)