Merge pull request #4542 from ivanov/history-clear

new `ipython history clear` subcommand

This new subcommand is equivalent to ipython history trim --HistoryTrim.keep=0, which is now supported (and also has a more convenient --keep alias)

This command comes with a fix to bash completion of flags for ipython history subcmd

also included is a tiny fix for nbconvert completion that was pointed out by @jakobgager in  #4528

also included is a change to our utils.io.ask_yes_no function that allows for specifying the behavior of a KeyboardInterrupt.

docs/source/whatsnew/pr/bash-completion.rst

@@ -0,0 +1,1 b''
+* bash completion updated with support for all ipython subcommands and flags, including nbconvert

docs/source/whatsnew/pr/history-clear.rst

@@ -0,0 +1,4 b''
+* ``ipython history trim``: added ``--keep=<N>`` as an alias for the more verbose
+  ``--HistoryTrim.keep=<N>``
+* new ``ipython history clear`` subcommand, which is the same as the newly supported
+  ``ipython history trim --keep=0``

IPython/core/historyapp.py

@@ -1,119 +1,159 b''
 # encoding: utf-8
 """
 An application for managing IPython history.
 
 To be invoked as the `ipython history` subcommand.
 """
 from __future__ import print_function
 
 import os
 import sqlite3
 
 from IPython.config.application import Application
 from IPython.core.application import BaseIPythonApplication
 from IPython.utils.traitlets import Bool, Int, Dict
+from IPython.utils.io import ask_yes_no
 
 trim_hist_help = """Trim the IPython history database to the last 1000 entries.
 
 This actually copies the last 1000 entries to a new database, and then replaces
-the old file with the new.
+the old file with the new. Use the `--keep=` argument to specify a number
+other than 1000.
 """
 
+clear_hist_help = """Clear the IPython history database, deleting all entries.
+
+Because this is a destructive operation, IPython will prompt the user if they
+really want to do this. Passing a `-f` flag will force clearing without a
+prompt.
+
+This is an handy alias to `ipython history trim --keep=0`
+"""
+
+
 class HistoryTrim(BaseIPythonApplication):
     description = trim_hist_help
     
     backup = Bool(False, config=True,
         help="Keep the old history file as history.sqlite.<N>")
     
     keep = Int(1000, config=True,
         help="Number of recent lines to keep in the database.")
     
     flags = Dict(dict(
         backup = ({'HistoryTrim' : {'backup' : True}},
-            "Set Application.log_level to 0, maximizing log output."
+            backup.get_metadata('help')
         )
     ))
+
+    aliases=Dict(dict(
+        keep = 'HistoryTrim.keep'
+    ))
     
     def start(self):
         profile_dir = self.profile_dir.location
         hist_file = os.path.join(profile_dir, 'history.sqlite')
         con = sqlite3.connect(hist_file)
 
         # Grab the recent history from the current database.
         inputs = list(con.execute('SELECT session, line, source, source_raw FROM '
                                 'history ORDER BY session DESC, line DESC LIMIT ?', (self.keep+1,)))
         if len(inputs) <= self.keep:
             print("There are already at most %d entries in the history database." % self.keep)
-            print("Not doing anything.")
+            print("Not doing anything. Use --keep= argument to keep fewer entries")
             return
         
         print("Trimming history to the most recent %d entries." % self.keep)
         
         inputs.pop() # Remove the extra element we got to check the length.
         inputs.reverse()
-        first_session = inputs[0][0]
-        outputs = list(con.execute('SELECT session, line, output FROM '
-                                   'output_history WHERE session >= ?', (first_session,)))
-        sessions = list(con.execute('SELECT session, start, end, num_cmds, remark FROM '
-                                    'sessions WHERE session >= ?', (first_session,)))
+        if inputs:
+            first_session = inputs[0][0]
+            outputs = list(con.execute('SELECT session, line, output FROM '
+                                       'output_history WHERE session >= ?', (first_session,)))
+            sessions = list(con.execute('SELECT session, start, end, num_cmds, remark FROM '
+                                        'sessions WHERE session >= ?', (first_session,)))
         con.close()
         
         # Create the new history database.
         new_hist_file = os.path.join(profile_dir, 'history.sqlite.new')
         i = 0
         while os.path.exists(new_hist_file):
             # Make sure we don't interfere with an existing file.
             i += 1
             new_hist_file = os.path.join(profile_dir, 'history.sqlite.new'+str(i))
         new_db = sqlite3.connect(new_hist_file)
         new_db.execute("""CREATE TABLE IF NOT EXISTS sessions (session integer
                             primary key autoincrement, start timestamp,
                             end timestamp, num_cmds integer, remark text)""")
         new_db.execute("""CREATE TABLE IF NOT EXISTS history
                         (session integer, line integer, source text, source_raw text,
                         PRIMARY KEY (session, line))""")
         new_db.execute("""CREATE TABLE IF NOT EXISTS output_history
                         (session integer, line integer, output text,
                         PRIMARY KEY (session, line))""")
         new_db.commit()
 
 
-        with new_db:
-            # Add the recent history into the new database.
-            new_db.executemany('insert into sessions values (?,?,?,?,?)', sessions)
-            new_db.executemany('insert into history values (?,?,?,?)', inputs)
-            new_db.executemany('insert into output_history values (?,?,?)', outputs)
+        if inputs:
+            with new_db:
+                # Add the recent history into the new database.
+                new_db.executemany('insert into sessions values (?,?,?,?,?)', sessions)
+                new_db.executemany('insert into history values (?,?,?,?)', inputs)
+                new_db.executemany('insert into output_history values (?,?,?)', outputs)
         new_db.close()
 
         if self.backup:
             i = 1
             backup_hist_file = os.path.join(profile_dir, 'history.sqlite.old.%d' % i)
             while os.path.exists(backup_hist_file):
                 i += 1
                 backup_hist_file = os.path.join(profile_dir, 'history.sqlite.old.%d' % i)
             os.rename(hist_file, backup_hist_file)
             print("Backed up longer history file to", backup_hist_file)
         else:
             os.remove(hist_file)
         
         os.rename(new_hist_file, hist_file)
 
+class HistoryClear(HistoryTrim):
+    description = clear_hist_help
+    keep = Int(0, config=False,
+        help="Number of recent lines to keep in the database.")
+    
+    force = Bool(False, config=True,
+        help="Don't prompt user for confirmation")
+    
+    flags = Dict(dict(
+        force = ({'HistoryClear' : {'force' : True}},
+            force.get_metadata('help')),
+        f = ({'HistoryTrim' : {'force' : True}},
+            force.get_metadata('help')
+        )
+    ))
+    aliases = Dict()
+
+    def start(self):
+        if self.force or ask_yes_no("Really delete all ipython history? ",
+                default="no", interrupt="no"):
+            HistoryTrim.start(self)
 
 class HistoryApp(Application):
     name = u'ipython-history'
     description = "Manage the IPython history database."
 
     subcommands = Dict(dict(
         trim = (HistoryTrim, HistoryTrim.description.splitlines()[0]),
+        clear = (HistoryClear, HistoryClear.description.splitlines()[0]),
     ))
 
     def start(self):
         if self.subapp is None:
             print("No subcommand specified. Must specify one of: %s" % \
                                                     (self.subcommands.keys()))
             print()
             self.print_description()
             self.print_subcommands()
             self.exit(1)
         else:
             return self.subapp.start()

IPython/utils/io.py

@@ -1,229 +1,232 b''
 # encoding: utf-8
 """
 IO related utilities.
 """
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2008-2011  The IPython Development Team
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #-----------------------------------------------------------------------------
 from __future__ import print_function
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 import os
 import sys
 import tempfile
 from .capture import CapturedIO, capture_output
 from .py3compat import string_types, input
 
 #-----------------------------------------------------------------------------
 # Code
 #-----------------------------------------------------------------------------
 
 
 class IOStream:
 
     def __init__(self,stream, fallback=None):
         if not hasattr(stream,'write') or not hasattr(stream,'flush'):
             if fallback is not None:
                 stream = fallback
             else:
                 raise ValueError("fallback required, but not specified")
         self.stream = stream
         self._swrite = stream.write
 
         # clone all methods not overridden:
         def clone(meth):
             return not hasattr(self, meth) and not meth.startswith('_')
         for meth in filter(clone, dir(stream)):
             setattr(self, meth, getattr(stream, meth))
 
     def write(self,data):
         try:
             self._swrite(data)
         except:
             try:
                 # print handles some unicode issues which may trip a plain
                 # write() call.  Emulate write() by using an empty end
                 # argument.
                 print(data, end='', file=self.stream)
             except:
                 # if we get here, something is seriously broken.
                 print('ERROR - failed to write data to stream:', self.stream,
                       file=sys.stderr)
 
     def writelines(self, lines):
         if isinstance(lines, string_types):
             lines = [lines]
         for line in lines:
             self.write(line)
 
     # This class used to have a writeln method, but regular files and streams
     # in Python don't have this method. We need to keep this completely
     # compatible so we removed it.
 
     @property
     def closed(self):
         return self.stream.closed
 
     def close(self):
         pass
 
 # setup stdin/stdout/stderr to sys.stdin/sys.stdout/sys.stderr
 devnull = open(os.devnull, 'a')
 stdin = IOStream(sys.stdin, fallback=devnull)
 stdout = IOStream(sys.stdout, fallback=devnull)
 stderr = IOStream(sys.stderr, fallback=devnull)
 
 class IOTerm:
     """ Term holds the file or file-like objects for handling I/O operations.
 
     These are normally just sys.stdin, sys.stdout and sys.stderr but for
     Windows they can can replaced to allow editing the strings before they are
     displayed."""
 
     # In the future, having IPython channel all its I/O operations through
     # this class will make it easier to embed it into other environments which
     # are not a normal terminal (such as a GUI-based shell)
     def __init__(self, stdin=None, stdout=None, stderr=None):
         mymodule = sys.modules[__name__]
         self.stdin  = IOStream(stdin, mymodule.stdin)
         self.stdout = IOStream(stdout, mymodule.stdout)
         self.stderr = IOStream(stderr, mymodule.stderr)
 
 
 class Tee(object):
     """A class to duplicate an output stream to stdout/err.
 
     This works in a manner very similar to the Unix 'tee' command.
 
     When the object is closed or deleted, it closes the original file given to
     it for duplication.
     """
     # Inspired by:
     # http://mail.python.org/pipermail/python-list/2007-May/442737.html
 
     def __init__(self, file_or_name, mode="w", channel='stdout'):
         """Construct a new Tee object.
 
         Parameters
         ----------
         file_or_name : filename or open filehandle (writable)
           File that will be duplicated
 
         mode : optional, valid mode for open().
           If a filename was give, open with this mode.
 
         channel : str, one of ['stdout', 'stderr']
         """
         if channel not in ['stdout', 'stderr']:
             raise ValueError('Invalid channel spec %s' % channel)
 
         if hasattr(file_or_name, 'write') and hasattr(file_or_name, 'seek'):
             self.file = file_or_name
         else:
             self.file = open(file_or_name, mode)
         self.channel = channel
         self.ostream = getattr(sys, channel)
         setattr(sys, channel, self)
         self._closed = False
 
     def close(self):
         """Close the file and restore the channel."""
         self.flush()
         setattr(sys, self.channel, self.ostream)
         self.file.close()
         self._closed = True
 
     def write(self, data):
         """Write data to both channels."""
         self.file.write(data)
         self.ostream.write(data)
         self.ostream.flush()
 
     def flush(self):
         """Flush both channels."""
         self.file.flush()
         self.ostream.flush()
 
     def __del__(self):
         if not self._closed:
             self.close()
 
 
-def ask_yes_no(prompt,default=None):
+def ask_yes_no(prompt, default=None, interrupt=None):
     """Asks a question and returns a boolean (y/n) answer.
 
     If default is given (one of 'y','n'), it is used if the user input is
-    empty. Otherwise the question is repeated until an answer is given.
+    empty. If interrupt is given (one of 'y','n'), it is used if the user
+    presses Ctrl-C. Otherwise the question is repeated until an answer is
+    given.
 
     An EOF is treated as the default answer.  If there is no default, an
     exception is raised to prevent infinite loops.
 
     Valid answers are: y/yes/n/no (match is not case sensitive)."""
 
     answers = {'y':True,'n':False,'yes':True,'no':False}
     ans = None
     while ans not in answers.keys():
         try:
             ans = input(prompt+' ').lower()
             if not ans:  # response was an empty string
                 ans = default
         except KeyboardInterrupt:
-            pass
+            if interrupt:
+                ans = interrupt
         except EOFError:
             if default in answers.keys():
                 ans = default
                 print()
             else:
                 raise
 
     return answers[ans]
 
 
 def temp_pyfile(src, ext='.py'):
     """Make a temporary python file, return filename and filehandle.
 
     Parameters
     ----------
     src : string or list of strings (no need for ending newlines if list)
       Source code to be written to the file.
 
     ext : optional, string
       Extension for the generated file.
 
     Returns
     -------
     (filename, open filehandle)
       It is the caller's responsibility to close the open file and unlink it.
     """
     fname = tempfile.mkstemp(ext)[1]
     f = open(fname,'w')
     f.write(src)
     f.flush()
     return fname, f
 
 
 def raw_print(*args, **kw):
     """Raw print to sys.__stdout__, otherwise identical interface to print()."""
 
     print(*args, sep=kw.get('sep', ' '), end=kw.get('end', '\n'),
           file=sys.__stdout__)
     sys.__stdout__.flush()
 
 
 def raw_print_err(*args, **kw):
     """Raw print to sys.__stderr__, otherwise identical interface to print()."""
 
     print(*args, sep=kw.get('sep', ' '), end=kw.get('end', '\n'),
           file=sys.__stderr__)
     sys.__stderr__.flush()
 
 
 # Short aliases for quick debugging, do NOT use these in production code.
 rprint = raw_print
 rprinte = raw_print_err

examples/core/ipython-completion.bash

@@ -1,115 +1,131 b''
 # load with: . ipython-completion.bash
 
 if [[ -n ${ZSH_VERSION-} ]]; then
     autoload -Uz bashcompinit && bashcompinit
 fi
 
 _ipython_get_flags()
 {
     local url=$1
     local var=$2
     local dash=$3
     if [[ "$url $var" == $__ipython_complete_last ]]; then
         opts=$__ipython_complete_last_res
         return
     fi
     # pylab and profile don't need the = and the
     # version without simplifies the special cased completion
     opts=$(ipython ${url} --help-all | grep -E "^-{1,2}[^-]" | sed -e "s/<.*//" -e "s/[^=]$/& /" -e "s/^--pylab=$//" -e "s/^--profile=$/--profile /")
     __ipython_complete_last="$url $var"
     __ipython_complete_last_res="$opts"
 }
 
 _ipython()
 {
     local cur=${COMP_WORDS[COMP_CWORD]}
     local prev=${COMP_WORDS[COMP_CWORD - 1]}
-    local subcommands="notebook qtconsole console kernel profile locate history nbconvert"
+    local subcommands="notebook qtconsole console kernel profile locate history nbconvert "
     local opts=""
     if [ -z "$__ipython_complete_baseopts" ]; then
         _ipython_get_flags baseopts
         __ipython_complete_baseopts="${opts}"
     fi
     local baseopts="$__ipython_complete_baseopts"
     local mode=""
     for i in "${COMP_WORDS[@]}"; do
         [ "$cur" = "$i" ] && break
         if [[ ${subcommands} == *${i}* ]]; then
             mode="$i"
             break
         elif [[ ${i} == "--"* ]]; then
             mode="nosubcommand"
             break
         fi
     done
 
 
     if [[ ${cur} == -* ]]; then
         case $mode in
-            "notebook" | "qtconsole" | "console" | "kernel")
+            "notebook" | "qtconsole" | "console" | "kernel" | "nbconvert")
                 _ipython_get_flags $mode
                 opts=$"${opts} ${baseopts}"
                 ;;
-            "locate" | "history" | "profile")
+            "locate" | "profile")
                 _ipython_get_flags $mode
+                ;;
+            "history")
+                if [[ $COMP_CWORD -ge 3 ]]; then
+                    # 'history trim' and 'history clear' covered by next line
+                    _ipython_get_flags history\ "${COMP_WORDS[2]}"
+                else
+                    _ipython_get_flags $mode
+
+                fi
                 opts=$"${opts}"
                 ;;
             *)
                 opts=$baseopts
         esac
         # don't drop the trailing space
         local IFS=$'\t\n'
         COMPREPLY=( $(compgen -W "${opts}" -- ${cur}) )
         return 0
     elif [[ $mode == "profile" ]]; then
-        opts="list create locate"
+        opts="list 	create 	locate "
+        local IFS=$'\t\n'
         COMPREPLY=( $(compgen -W "${opts}" -- ${cur}) )
     elif [[ $mode == "history" ]]; then
-        opts="trim"
+        if [[ $COMP_CWORD -ge 3 ]]; then
+            # drop into flags
+            opts="--"
+        else
+            opts="trim 	clear "
+        fi
+        local IFS=$'\t\n'
         COMPREPLY=( $(compgen -W "${opts}" -- ${cur}) )
     elif [[ $mode == "locate" ]]; then
         opts="profile"
         COMPREPLY=( $(compgen -W "${opts}" -- ${cur}) )
     elif [[ ${prev} == "--pylab"* ]] || [[ ${prev} == "--gui"* ]]; then
         if [ -z "$__ipython_complete_pylab" ]; then
             __ipython_complete_pylab=`cat <<EOF | python -
 try:
     import IPython.core.shellapp as mod;
     for k in mod.InteractiveShellApp.pylab.values:
         print "%s " % k
 except:
     pass
 EOF
         `
         fi
         local IFS=$'\t\n'
         COMPREPLY=( $(compgen -W "${__ipython_complete_pylab}" -- ${cur}) )
     elif [[ ${prev} == "--profile"* ]]; then
         if [ -z  "$__ipython_complete_profiles" ]; then
         __ipython_complete_profiles=`cat <<EOF | python -
 try:
     import IPython.core.profileapp
     for k in IPython.core.profileapp.list_bundled_profiles():
         print "%s " % k
     p = IPython.core.profileapp.ProfileList()
     for k in IPython.core.profileapp.list_profiles_in(p.ipython_dir):
         print "%s " % k
 except:
     pass
 EOF
         `
         fi
         local IFS=$'\t\n'
         COMPREPLY=( $(compgen -W "${__ipython_complete_profiles}" -- ${cur}) )
     else
         if [ "$COMP_CWORD" == 1 ]; then
             local IFS=$'\t\n'
             local sub=$(echo $subcommands | sed -e "s/ / \t/g")
             COMPREPLY=( $(compgen -W "${sub}" -- ${cur}) )
         else
             COMPREPLY=( $(compgen -f -- ${cur}) )
         fi
     fi
 
 }
 complete -o default -o nospace -F _ipython ipython