ENH: Docstrings for the user namespace API.

IPython/ipapi.py

@@ -1,646 +1,686 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
 
 try: # Python 2.3 compatibility
     set
 except NameError:
     import sets
     set = sets.Set
 
 # 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 UsageError(Exception):
     """ Error in magic function arguments, etc.
     
     Something that probably won't warrant a full traceback, but should
     nevertheless interrupt a macro / batch file.   
     """
 
 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.user_ns['_ip'] = self
 
         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 = {}
 
         self.dbg = DebugTools(self)
         
         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__)
         old = getattr(self.IP, "magic_" + magicname, None)
         if old:
             self.dbg.debug_stack("Magic redefinition '%s', old %s" % (magicname,
                                  old))
             
         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.
         """
 
         def cleanup_ipy_script(script):
             """ Make a script safe for _ip.runlines() 
             
             - Removes empty lines
             - Suffixes all indented blocks that end with unindented lines with empty lines
             
             """
             res = []
             lines = script.splitlines()
 
             level = 0
             for l in lines:
                 lstripped = l.lstrip()
                 stripped = l.strip()                
                 if not stripped:
                     continue
                 newlevel = len(l) - len(lstripped)
                 def is_secondary_block_start(s):
                     if not s.endswith(':'):
                         return False
                     if (s.startswith('elif') or 
                         s.startswith('else') or 
                         s.startswith('except') or
                         s.startswith('finally')):
                         return True
                         
                 if level > 0 and newlevel == 0 and not is_secondary_block_start(stripped): 
                     # add empty line
                     res.append('')
                     
                 res.append(l)
                 level = newlevel
             return '\n'.join(res) + '\n'
         
         if isinstance(lines,basestring):
             script = lines            
         else:
             script = '\n'.join(lines)
         clean=cleanup_ipy_script(script)
         # print "_ip.runlines() script:\n",clean #dbg
         self.IP.runlines(clean)
     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, or a
          dict with name/value pairs.
 
          - 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')
             ...
             
             # To expose *ALL* the local variables from the function, use:
             ip.to_user_ns(locals())
 
             ...
             # return           
         
 
         If you need to rename variables, the dict input makes it easy.  For
         example, this call exposes variables 'foo' as 'x' and 'bar' as 'y'
         in IPython user namespace:
 
         ip.to_user_ns(dict(x=foo,y=bar))    
         """
 
         # print 'vars given:',vars # dbg
         
         # We need a dict of name/value pairs to do namespace updates.
         if isinstance(vars,dict):
             # If a dict was given, no need to change anything.
             vdict = vars
         elif isinstance(vars,basestring):
             # If a string with names was given, get the caller's frame to
             # evaluate the given names in
             cf = sys._getframe(1)
             vdict = {}
             for name in vars.split():
                 try:
                     vdict[name] = eval(name,cf.f_globals,cf.f_locals)
                 except:
                     print ('could not get var. %s from %s' %
                     (name,cf.f_code.co_name))
         else:
             raise ValueError('vars must be a string or a dict')
             
         # Propagate variables to user namespace
         self.user_ns.update(vdict)
 
         # And configure interactive visibility
         config_ns = self.IP.user_config_ns
         if interactive:
             for name,val in vdict.iteritems():
                 config_ns.pop(name,None)
         else:
             for name,val in vdict.iteritems():
                 config_ns[name] = val                    
 
 
     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 itpl(self, s, depth = 1):
         """ Expand Itpl format string s.
         
         Only callable from command line (i.e. prefilter results);
         If you use in your scripts, you need to use a bigger depth!
         """
         return self.IP.var_expand(s, depth)
         
     def defalias(self, name, cmd):
         """ Define a new alias
         
         _ip.defalias('bb','bldmake bldfiles')
         
         Creates a new alias named 'bb' in ipython user namespace
         """
 
         self.dbg.check_hotname(name)
         
 
         if name in self.IP.alias_table:
             self.dbg.debug_stack("Alias redefinition: '%s' => '%s' (old '%s')" %
                              (name, cmd, self.IP.alias_table[name]))
             
 
         if callable(cmd):
             self.IP.alias_table[name] = cmd
             import IPython.shadowns
             setattr(IPython.shadowns, name,cmd)
             return
             
         if isinstance(cmd,basestring):
             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.')
                   
             self.IP.alias_table[name] = (nargs,cmd)
             return
         
         # just put it in - it's probably (0,'foo')
         self.IP.alias_table[name] = 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):
         """ Load an extension.
         
         Some modules should (or must) be 'load()':ed, rather than just imported.
         
         Loading will do:
         
         - run init_ipython(ip)
         - run ipython_firstrun(ip)
         
         """
         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)
             
         if hasattr(m,'ipython_firstrun'):
             already_loaded = self.db.get('firstrun_done', set())
             if mod not in already_loaded:
                 m.ipython_firstrun(self)
                 already_loaded.add(mod)
                 self.db['firstrun_done'] = already_loaded
             
         self.extensions[mod] = m
         return m
 
 
 class DebugTools:
     """ Used for debugging mishaps in api usage
     
     So far, tracing redefinitions is supported.
     """
     
     def __init__(self, ip):
         self.ip = ip
         self.debugmode = False
         self.hotnames = set()
         
     def hotname(self, name_to_catch):
         self.hotnames.add(name_to_catch)
         
     def debug_stack(self, msg = None):
         if not self.debugmode:
             return
         
         import traceback
         if msg is not None:
             print '====== %s  ========' % msg
         traceback.print_stack()
 
     def check_hotname(self,name):
         if name in self.hotnames:
             self.debug_stack( "HotName '%s' caught" % name)
 
 def launch_new_instance(user_ns = None,shellclass = 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,shellclass)
     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.
+
+    This API is currently deprecated. Use ipapi.make_user_namespaces() instead
+    to make both the local and global namespace objects simultaneously.
+
+    :Parameters:
+        user_ns : dict-like, optional
+            The current user namespace. The items in this namespace should be
+            included in the output. If None, an appropriate blank namespace
+            should be created.
+
+    :Returns:
+        A dictionary-like object to be used as the local namespace of the
+        interpreter.
     """
 
     raise NotImplementedError
 
 
 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."""
+    interactive namespace and the global one where ipython is running.
+
+    This API is currently deprecated. Use ipapi.make_user_namespaces() instead
+    to make both the local and global namespace objects simultaneously.
+
+    :Parameters:
+        ns : dict, optional
+            The current user global namespace. The items in this namespace
+            should be included in the output. If None, an appropriate blank
+            namespace should be created.
+
+    :Returns:
+        A true dict to be used as the global namespace of the interpreter.
+    """
 
     raise NotImplementedError
 
 # Record the true objects in order to be able to test if the user has overridden
 # these API functions.
 _make_user_ns = make_user_ns
 _make_user_global_ns = make_user_global_ns
 
 
 def make_user_namespaces(user_ns = None,user_global_ns = None):
     """Return a valid local and global user interactive namespaces.
 
     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.  The default implementation returns the same dict for
     both the locals and the globals to allow functions to refer to variables in
     the namespace.  Customized implementations can return different dicts.  The
     locals dictionary can actually be anything following the basic mapping
     protocol of a dict, but the globals dict must be a true dict, not even
     a subclass.  It is recommended that any custom object for the locals
     namespace synchronize with the globals dict somehow.
 
     Raises TypeError if the provided globals namespace is not a true dict.
+
+    :Parameters:
+        user_ns : dict-like, optional
+            The current user namespace. The items in this namespace should be
+            included in the output. If None, an appropriate blank namespace
+            should be created.
+        user_global_ns : dict, optional
+            The current user global namespace. The items in this namespace
+            should be included in the output. If None, an appropriate blank
+            namespace should be created.
+
+    :Returns:
+        A tuple pair of dictionary-like object to be used as the local namespace
+        of the interpreter and a dict to be used as the global namespace.
     """
 
     if user_ns is None:
         if make_user_ns is not _make_user_ns:
             # Old API overridden.
             # FIXME: Issue DeprecationWarning, or just let the old API live on?
             user_ns = make_user_ns(user_ns)
         else:
             # 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__)
 
     if user_global_ns is None:
         if make_user_global_ns is not _make_user_global_ns:
             # Old API overridden.
             user_global_ns = make_user_global_ns(user_global_ns)
         else:
             user_global_ns = user_ns
     if type(user_global_ns) is not dict:
         raise TypeError("user_global_ns must be a true dict; got %r"
             % type(user_global_ns))
 
     return user_ns, user_global_ns
 
 
 def make_session(user_ns = None, shellclass = 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.Shell
     if shellclass is None:
         return IPython.Shell.start(user_ns)
     return shellclass(user_ns = user_ns)