Rewrite %history magic using magic_arguments

IPython/core/magics/history.py

@@ -16,10 +16,13 b' from __future__ import print_function'
 # Stdlib
 import os
 from io import open as io_open
+from argparse import Action
 
 # Our own packages
 from IPython.core.error import StdinNotImplementedError
 from IPython.core.magic import Magics, magics_class, line_magic
+from IPython.core.magic_arguments import (argument, magic_arguments,
+                                          parse_argstring)
 from IPython.testing.skipdoctest import skip_doctest
 from IPython.utils import io
 
@@ -27,16 +30,74 b' from IPython.utils import io'
 # Magics class implementation
 #-----------------------------------------------------------------------------
 
+
+class HistoryArgLimitAction(Action):
+    def __call__(self, parser, namespace, values, option_string=None):
+        namespace.limit_specified = True
+        namespace.limit = values
+
+
 @magics_class
 class HistoryMagics(Magics):
 
+    @magic_arguments()
+    @argument(
+        '-n', dest='print_nums', action='store_true', default=False,
+        help="""
+        print line numbers for each input.
+        This feature is only available if numbered prompts are in use.
+        """)
+    @argument(
+        '-o', dest='get_output', action='store_true', default=False,
+        help="also print outputs for each input.")
+    @argument(
+        '-p', dest='pyprompts', action='store_true', default=False,
+        help="""
+        print classic '>>>' python prompts before each input.
+        This is useful for making documentation, and in conjunction
+        with -o, for producing doctest-ready output.
+        """)
+    @argument(
+        '-t', dest='raw', action='store_false', default=True,
+        help="""
+        print the 'translated' history, as IPython understands it.
+        IPython filters your input and converts it all into valid Python
+        source before executing it (things like magics or aliases are turned
+        into function calls, for example). With this option, you'll see the
+        native history instead of the user-entered version: '%%cd /' will be
+        seen as 'get_ipython().magic("%%cd /")' instead of '%%cd /'.
+        """)
+    @argument(
+        '-f', dest='filename',
+        help="""
+        FILENAME: instead of printing the output to the screen, redirect
+        it to the given file.  The file is always overwritten, though *when
+        it can*, IPython asks for confirmation first. In particular, running
+        the command 'history -f FILENAME' from the IPython Notebook
+        interface will replace FILENAME even if it already exists *without*
+        confirmation.
+        """)
+    @argument(
+        '-g', dest='pattern', nargs='*', default=None,
+        help="""
+        treat the arg as a pattern to grep for in (full) history.
+        This includes the saved history (almost all commands ever written).
+        The pattern may contain '?' to match one unknown character and '*'
+        to match any number of unknown characters. Use '%%hist -g' to show
+        full saved history (may be very long).
+        """)
+    @argument(
+        '-l', dest='limit', type=int, nargs='?', action=HistoryArgLimitAction,
+        help="""
+        get the last n lines from all sessions. Specify n as a single
+        arg, or the default is the last 10 lines.
+        """)
+    @argument('range', nargs='*')
     @skip_doctest
     @line_magic
     def history(self, parameter_s = ''):
         """Print input history (_i<n> variables), with most recent last.
 
-        %history [-o -p -t -n] [-f filename] [range | -g pattern | -l number]
-
         By default, input history is printed without line numbers so it can be
         directly pasted into an editor. Use -n to show them.
 
@@ -52,43 +113,6 b' class HistoryMagics(Magics):'
 
         The same syntax is used by %macro, %save, %edit, %rerun
 
-        Options:
-
-          -n: print line numbers for each input.
-          This feature is only available if numbered prompts are in use.
-
-          -o: also print outputs for each input.
-
-          -p: print classic '>>>' python prompts before each input.  This is
-           useful for making documentation, and in conjunction with -o, for
-           producing doctest-ready output.
-
-          -r: (default) print the 'raw' history, i.e. the actual commands you
-           typed.
-
-          -t: print the 'translated' history, as IPython understands it.
-          IPython filters your input and converts it all into valid Python
-          source before executing it (things like magics or aliases are turned
-          into function calls, for example). With this option, you'll see the
-          native history instead of the user-entered version: '%cd /' will be
-          seen as 'get_ipython().magic("%cd /")' instead of '%cd /'.
-
-          -g: treat the arg as a pattern to grep for in (full) history.
-          This includes the saved history (almost all commands ever written).
-          The pattern may contain '?' to match one unknown character and '*'
-          to match any number of unknown characters. Use '%hist -g' to show
-          full saved history (may be very long).
-
-          -l: get the last n lines from all sessions. Specify n as a single
-          arg, or the default is the last 10 lines.
-
-          -f FILENAME: instead of printing the output to the screen, redirect
-           it to the given file.  The file is always overwritten, though *when
-           it can*, IPython asks for confirmation first. In particular, running
-           the command 'history -f FILENAME' from the IPython Notebook
-           interface will replace FILENAME even if it already exists *without*
-           confirmation.
-
         Examples
         --------
         ::
@@ -104,7 +128,7 b' class HistoryMagics(Magics):'
             print('This feature is only available if numbered prompts '
                   'are in use.')
             return
-        opts,args = self.parse_options(parameter_s,'noprtglf:',mode='string')
+        args = parse_argstring(self.history, parameter_s)
 
         # For brevity
         history_manager = self.shell.history_manager
@@ -116,9 +140,8 b' class HistoryMagics(Magics):'
             return "%s/%s" % (session, line)
 
         # Check if output to specific file was requested.
-        try:
-            outfname = opts['f']
-        except KeyError:
+        outfname = args.filename
+        if not outfname:
             outfile = io.stdout  # default
             # We don't want to close stdout at the end!
             close_at_end = False
@@ -135,27 +158,27 b' class HistoryMagics(Magics):'
             outfile = io_open(outfname, 'w', encoding='utf-8')
             close_at_end = True
 
-        print_nums = 'n' in opts
-        get_output = 'o' in opts
-        pyprompts = 'p' in opts
-        # Raw history is the default
-        raw = not('t' in opts)
+        print_nums = args.print_nums
+        get_output = args.get_output
+        pyprompts = args.pyprompts
+        raw = args.raw
 
         pattern = None
 
-        if 'g' in opts:         # Glob search
-            pattern = "*" + args + "*" if args else "*"
+        if args.pattern is not None:
+            if args.pattern:
+                pattern = "*" + " ".join(args.pattern) + "*"
+            else:
+                pattern = "*"
             hist = history_manager.search(pattern, raw=raw, output=get_output)
             print_nums = True
-        elif 'l' in opts:       # Get 'tail'
-            try:
-                n = int(args)
-            except (ValueError, IndexError):
-                n = 10
+        elif getattr(args, 'limit_specified', False):
+            n = 10 if args.limit is None else args.limit
             hist = history_manager.get_tail(n, raw=raw, output=get_output)
         else:
-            if args:            # Get history by ranges
-                hist = history_manager.get_range_by_str(args, raw, get_output)
+            if args.range:      # Get history by ranges
+                hist = history_manager.get_range_by_str(" ".join(args.range),
+                                                        raw, get_output)
             else:               # Just get history for the current session
                 hist = history_manager.get_range(raw=raw, output=get_output)