added scandir and fixed how isexec is created

IPython/core/magics/osm.py

@@ -1,792 +1,828 b''
 """Implementation of magic functions for interaction with the OS.
 
 Note: this module is named 'osm' instead of 'os' to avoid a collision with the
 builtin.
 """
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 import io
 import os
 import re
 import sys
 from pprint import pformat
 
 from IPython.core import magic_arguments
 from IPython.core import oinspect
 from IPython.core import page
 from IPython.core.alias import AliasError, Alias
 from IPython.core.error import UsageError
 from IPython.core.magic import  (
     Magics, compress_dhist, magics_class, line_magic, cell_magic, line_cell_magic
 )
 from IPython.testing.skipdoctest import skip_doctest
 from IPython.utils.openpy import source_to_unicode
 from IPython.utils.process import abbrev_cwd
 from IPython.utils.terminal import set_term_title
+from os import DirEntry
 
 
 @magics_class
 class OSMagics(Magics):
     """Magics to interact with the underlying OS (shell-type functionality).
     """
 
+    def __init__(self, shell=None, **kwargs):
+
+        # Now define isexec in a cross platform manner.
+        self.is_posix: bool = False
+        self.execre = None
+        if os.name == 'posix':
+            self.is_posix = True
+        else:
+            try:
+                winext = os.environ['pathext'].replace(';','|').replace('.','')
+            except KeyError:
+                winext = 'exe|com|bat|py'
+            
+            self.execre = re.compile(r'(.*)\.(%s)$' % winext,re.IGNORECASE)
+
+        # call up the chain
+        super(OSMagics, self).__init__(shell=shell, **kwargs)
+
+
+    @skip_doctest
+    def _isexec_POSIX(self, f:DirEntry) -> bool:
+        """
+            Test for executible on a POSIX system
+        """
+        return f.is_file() and os.access(f.path, os.X_OK)
+
+    
+    @skip_doctest
+    def _isexec_WIN(self, f:DirEntry) -> int:
+        """
+            Test for executible file on non POSIX system
+        """
+        return f.is_file() and self.execre.match(f.name) is not None
+
+    @skip_doctest
+    def isexec(self, f:DirEntry) -> bool:
+        """
+            Test for executible file on non POSIX system
+        """
+        if self.is_posix:
+            return self._isexec_POSIX(f)
+        else:
+            return self._isexec_WIN(f)
+
+
     @skip_doctest
     @line_magic
     def alias(self, parameter_s=''):
         """Define an alias for a system command.
 
         '%alias alias_name cmd' defines 'alias_name' as an alias for 'cmd'
 
         Then, typing 'alias_name params' will execute the system command 'cmd
         params' (from your underlying operating system).
 
         Aliases have lower precedence than magic functions and Python normal
         variables, so if 'foo' is both a Python variable and an alias, the
         alias can not be executed until 'del foo' removes the Python variable.
 
         You can use the %l specifier in an alias definition to represent the
         whole line when the alias is called.  For example::
 
           In [2]: alias bracket echo "Input in brackets: <%l>"
           In [3]: bracket hello world
           Input in brackets: <hello world>
 
         You can also define aliases with parameters using %s specifiers (one
         per parameter)::
 
           In [1]: alias parts echo first %s second %s
           In [2]: %parts A B
           first A second B
           In [3]: %parts A
           Incorrect number of arguments: 2 expected.
           parts is an alias to: 'echo first %s second %s'
 
         Note that %l and %s are mutually exclusive.  You can only use one or
         the other in your aliases.
 
         Aliases expand Python variables just like system calls using ! or !!
         do: all expressions prefixed with '$' get expanded.  For details of
         the semantic rules, see PEP-215:
         http://www.python.org/peps/pep-0215.html.  This is the library used by
         IPython for variable expansion.  If you want to access a true shell
         variable, an extra $ is necessary to prevent its expansion by
         IPython::
 
           In [6]: alias show echo
           In [7]: PATH='A Python string'
           In [8]: show $PATH
           A Python string
           In [9]: show $$PATH
           /usr/local/lf9560/bin:/usr/local/intel/compiler70/ia32/bin:...
 
         You can use the alias facility to access all of $PATH.  See the %rehashx
         function, which automatically creates aliases for the contents of your
         $PATH.
 
         If called with no parameters, %alias prints the current alias table
         for your system.  For posix systems, the default aliases are 'cat',
         'cp', 'mv', 'rm', 'rmdir', and 'mkdir', and other platform-specific
         aliases are added.  For windows-based systems, the default aliases are
         'copy', 'ddir', 'echo', 'ls', 'ldir', 'mkdir', 'ren', and 'rmdir'.
 
         You can see the definition of alias by adding a question mark in the
         end::
 
           In [1]: cat?
           Repr: <alias cat for 'cat'>"""
 
         par = parameter_s.strip()
         if not par:
             aliases = sorted(self.shell.alias_manager.aliases)
             # stored = self.shell.db.get('stored_aliases', {} )
             # for k, v in stored:
             #     atab.append(k, v[0])
 
             print("Total number of aliases:", len(aliases))
             sys.stdout.flush()
             return aliases
 
         # Now try to define a new one
         try:
             alias,cmd = par.split(None, 1)
         except TypeError:
             print(oinspect.getdoc(self.alias))
             return
         
         try:
             self.shell.alias_manager.define_alias(alias, cmd)
         except AliasError as e:
             print(e)
     # end magic_alias
 
     @line_magic
     def unalias(self, parameter_s=''):
         """Remove an alias"""
 
         aname = parameter_s.strip()
         try:
             self.shell.alias_manager.undefine_alias(aname)
         except ValueError as e:
             print(e)
             return
         
         stored = self.shell.db.get('stored_aliases', {} )
         if aname in stored:
             print("Removing %stored alias",aname)
             del stored[aname]
             self.shell.db['stored_aliases'] = stored
 
     @line_magic
     def rehashx(self, parameter_s=''):
         """Update the alias table with all executable files in $PATH.
 
         rehashx explicitly checks that every entry in $PATH is a file
         with execute access (os.X_OK).
 
         Under Windows, it checks executability as a match against a
         '|'-separated string of extensions, stored in the IPython config
         variable win_exec_ext.  This defaults to 'exe|com|bat'.
 
         This function also resets the root module cache of module completer,
         used on slow filesystems.
         """
         from IPython.core.alias import InvalidAliasError
 
         # for the benefit of module completer in ipy_completers.py
         del self.shell.db['rootmodules_cache']
 
         path = [os.path.abspath(os.path.expanduser(p)) for p in
             os.environ.get('PATH','').split(os.pathsep)]
 
         syscmdlist = []
-        # Now define isexec in a cross platform manner.
-        if os.name == 'posix':
-            isexec = lambda fname:os.path.isfile(fname) and \
-                     os.access(fname,os.X_OK)
-        else:
-            try:
-                winext = os.environ['pathext'].replace(';','|').replace('.','')
-            except KeyError:
-                winext = 'exe|com|bat|py'
-            if 'py' not in winext:
-                winext += '|py'
-            execre = re.compile(r'(.*)\.(%s)$' % winext,re.IGNORECASE)
-            isexec = lambda fname:os.path.isfile(fname) and execre.match(fname)
         savedir = os.getcwd()
 
         # Now walk the paths looking for executables to alias.
         try:
             # write the whole loop for posix/Windows so we don't have an if in
             # the innermost part
             if os.name == 'posix':
                 for pdir in path:
                     try:
                         os.chdir(pdir)
-                        dirlist = os.listdir(pdir)
                     except OSError:
                         continue
-                    for ff in dirlist:
-                        if isexec(ff):
-                            try:
-                                # Removes dots from the name since ipython
-                                # will assume names with dots to be python.
-                                if not self.shell.alias_manager.is_alias(ff):
-                                    self.shell.alias_manager.define_alias(
-                                        ff.replace('.',''), ff)
-                            except InvalidAliasError:
-                                pass
-                            else:
-                                syscmdlist.append(ff)
+                    with os.scandir(pdir) as dirlist:
+                        for ff in dirlist:
+                            if self.isexec(ff):
+                                fname = ff.name
+                                try:
+                                    # Removes dots from the name since ipython
+                                    # will assume names with dots to be python.
+                                    if not self.shell.alias_manager.is_alias(fname):
+                                        self.shell.alias_manager.define_alias(
+                                            fname.replace('.',''), fname)
+                                except InvalidAliasError:
+                                    pass
+                                else:
+                                    syscmdlist.append(fname)
             else:
                 no_alias = Alias.blacklist
                 for pdir in path:
                     try:
                         os.chdir(pdir)
-                        dirlist = os.listdir(pdir)
                     except OSError:
                         continue
-                    for ff in dirlist:
-                        base, ext = os.path.splitext(ff)
-                        if isexec(ff) and base.lower() not in no_alias:
-                            if ext.lower() == '.exe':
-                                ff = base
-                                try:
-                                    # Removes dots from the name since ipython
-                                    # will assume names with dots to be python.
-                                    self.shell.alias_manager.define_alias(
-                                        base.lower().replace('.',''), ff)
-                                except InvalidAliasError:
-                                    pass
-                                syscmdlist.append(ff)
+                    with os.scandir(pdir) as dirlist:
+                        for ff in dirlist:
+                            fname = ff.name
+                            base, ext = os.path.splitext(fname)
+                            if self.isexec(ff) and base.lower() not in no_alias:
+                                if ext.lower() == '.exe':
+                                    fname = base
+                                    try:
+                                        # Removes dots from the name since ipython
+                                        # will assume names with dots to be python.
+                                        self.shell.alias_manager.define_alias(
+                                            base.lower().replace('.',''), fname)
+                                    except InvalidAliasError:
+                                        pass
+                                    syscmdlist.append(fname)
             self.shell.db['syscmdlist'] = syscmdlist
         finally:
             os.chdir(savedir)
 
     @skip_doctest
     @line_magic
     def pwd(self, parameter_s=''):
         """Return the current working directory path.
 
         Examples
         --------
         ::
 
           In [9]: pwd
           Out[9]: '/home/tsuser/sprint/ipython'
         """
         try:
             return os.getcwd()
         except FileNotFoundError:
             raise UsageError("CWD no longer exists - please use %cd to change directory.")
 
     @skip_doctest
     @line_magic
     def cd(self, parameter_s=''):
         """Change the current working directory.
 
         This command automatically maintains an internal list of directories
         you visit during your IPython session, in the variable _dh. The
         command %dhist shows this history nicely formatted. You can also
         do 'cd -<tab>' to see directory history conveniently.
 
         Usage:
 
           cd 'dir': changes to directory 'dir'.
 
           cd -: changes to the last visited directory.
 
           cd -<n>: changes to the n-th directory in the directory history.
 
           cd --foo: change to directory that matches 'foo' in history
 
           cd -b <bookmark_name>: jump to a bookmark set by %bookmark
              (note: cd <bookmark_name> is enough if there is no
               directory <bookmark_name>, but a bookmark with the name exists.)
               'cd -b <tab>' allows you to tab-complete bookmark names.
 
         Options:
 
         -q: quiet.  Do not print the working directory after the cd command is
         executed.  By default IPython's cd command does print this directory,
         since the default prompts do not display path information.
 
         Note that !cd doesn't work for this purpose because the shell where
         !command runs is immediately discarded after executing 'command'.
 
         Examples
         --------
         ::
 
           In [10]: cd parent/child
           /home/tsuser/parent/child
         """
 
         try:
             oldcwd = os.getcwd()
         except FileNotFoundError:
             # Happens if the CWD has been deleted.
             oldcwd = None
 
         numcd = re.match(r'(-)(\d+)$',parameter_s)
         # jump in directory history by number
         if numcd:
             nn = int(numcd.group(2))
             try:
                 ps = self.shell.user_ns['_dh'][nn]
             except IndexError:
                 print('The requested directory does not exist in history.')
                 return
             else:
                 opts = {}
         elif parameter_s.startswith('--'):
             ps = None
             fallback = None
             pat = parameter_s[2:]
             dh = self.shell.user_ns['_dh']
             # first search only by basename (last component)
             for ent in reversed(dh):
                 if pat in os.path.basename(ent) and os.path.isdir(ent):
                     ps = ent
                     break
 
                 if fallback is None and pat in ent and os.path.isdir(ent):
                     fallback = ent
 
             # if we have no last part match, pick the first full path match
             if ps is None:
                 ps = fallback
 
             if ps is None:
                 print("No matching entry in directory history")
                 return
             else:
                 opts = {}
 
 
         else:
             opts, ps = self.parse_options(parameter_s, 'qb', mode='string')
         # jump to previous
         if ps == '-':
             try:
                 ps = self.shell.user_ns['_dh'][-2]
             except IndexError:
                 raise UsageError('%cd -: No previous directory to change to.')
         # jump to bookmark if needed
         else:
             if not os.path.isdir(ps) or 'b' in opts:
                 bkms = self.shell.db.get('bookmarks', {})
 
                 if ps in bkms:
                     target = bkms[ps]
                     print('(bookmark:%s) -> %s' % (ps, target))
                     ps = target
                 else:
                     if 'b' in opts:
                         raise UsageError("Bookmark '%s' not found.  "
                               "Use '%%bookmark -l' to see your bookmarks." % ps)
 
         # at this point ps should point to the target dir
         if ps:
             try:
                 os.chdir(os.path.expanduser(ps))
                 if hasattr(self.shell, 'term_title') and self.shell.term_title:
                     set_term_title(self.shell.term_title_format.format(cwd=abbrev_cwd()))
             except OSError:
                 print(sys.exc_info()[1])
             else:
                 cwd = os.getcwd()
                 dhist = self.shell.user_ns['_dh']
                 if oldcwd != cwd:
                     dhist.append(cwd)
                     self.shell.db['dhist'] = compress_dhist(dhist)[-100:]
 
         else:
             os.chdir(self.shell.home_dir)
             if hasattr(self.shell, 'term_title') and self.shell.term_title:
                 set_term_title(self.shell.term_title_format.format(cwd="~"))
             cwd = os.getcwd()
             dhist = self.shell.user_ns['_dh']
 
             if oldcwd != cwd:
                 dhist.append(cwd)
                 self.shell.db['dhist'] = compress_dhist(dhist)[-100:]
         if not 'q' in opts and self.shell.user_ns['_dh']:
             print(self.shell.user_ns['_dh'][-1])
 
     @line_magic
     def env(self, parameter_s=''):
         """Get, set, or list environment variables.
 
         Usage:\\
 
           %env: lists all environment variables/values
           %env var: get value for var
           %env var val: set value for var
           %env var=val: set value for var
           %env var=$val: set value for var, using python expansion if possible
         """
         if parameter_s.strip():
             split = '=' if '=' in parameter_s else ' '
             bits = parameter_s.split(split)
             if len(bits) == 1:
                 key = parameter_s.strip()
                 if key in os.environ:
                     return os.environ[key]
                 else:
                     err = "Environment does not have key: {0}".format(key)
                     raise UsageError(err)
             if len(bits) > 1:
                 return self.set_env(parameter_s)
         return dict(os.environ)
 
     @line_magic
     def set_env(self, parameter_s):
         """Set environment variables.  Assumptions are that either "val" is a
         name in the user namespace, or val is something that evaluates to a
         string.
 
         Usage:\\
           %set_env var val: set value for var
           %set_env var=val: set value for var
           %set_env var=$val: set value for var, using python expansion if possible
         """
         split = '=' if '=' in parameter_s else ' '
         bits = parameter_s.split(split, 1)
         if not parameter_s.strip() or len(bits)<2:
             raise UsageError("usage is 'set_env var=val'")
         var = bits[0].strip()
         val = bits[1].strip()
         if re.match(r'.*\s.*', var):
             # an environment variable with whitespace is almost certainly
             # not what the user intended.  what's more likely is the wrong
             # split was chosen, ie for "set_env cmd_args A=B", we chose
             # '=' for the split and should have chosen ' '.  to get around
             # this, users should just assign directly to os.environ or use
             # standard magic {var} expansion.
             err = "refusing to set env var with whitespace: '{0}'"
             err = err.format(val)
             raise UsageError(err)
         os.environ[var] = val
         print('env: {0}={1}'.format(var,val))
 
     @line_magic
     def pushd(self, parameter_s=''):
         """Place the current dir on stack and change directory.
 
         Usage:\\
           %pushd ['dirname']
         """
 
         dir_s = self.shell.dir_stack
         tgt = os.path.expanduser(parameter_s)
         cwd = os.getcwd().replace(self.shell.home_dir,'~')
         if tgt:
             self.cd(parameter_s)
         dir_s.insert(0,cwd)
         return self.shell.magic('dirs')
 
     @line_magic
     def popd(self, parameter_s=''):
         """Change to directory popped off the top of the stack.
         """
         if not self.shell.dir_stack:
             raise UsageError("%popd on empty stack")
         top = self.shell.dir_stack.pop(0)
         self.cd(top)
         print("popd ->",top)
 
     @line_magic
     def dirs(self, parameter_s=''):
         """Return the current directory stack."""
 
         return self.shell.dir_stack
 
     @line_magic
     def dhist(self, parameter_s=''):
         """Print your history of visited directories.
 
         %dhist       -> print full history\\
         %dhist n     -> print last n entries only\\
         %dhist n1 n2 -> print entries between n1 and n2 (n2 not included)\\
 
         This history is automatically maintained by the %cd command, and
         always available as the global list variable _dh. You can use %cd -<n>
         to go to directory number <n>.
 
         Note that most of time, you should view directory history by entering
         cd -<TAB>.
 
         """
 
         dh = self.shell.user_ns['_dh']
         if parameter_s:
+            args = []
             try:
                 args = map(int,parameter_s.split())
             except:
                 self.arg_err(self.dhist)
                 return
             if len(args) == 1:
                 ini,fin = max(len(dh)-(args[0]),0),len(dh)
             elif len(args) == 2:
                 ini,fin = args
                 fin = min(fin, len(dh))
             else:
                 self.arg_err(self.dhist)
                 return
         else:
             ini,fin = 0,len(dh)
         print('Directory history (kept in _dh)')
         for i in range(ini, fin):
             print("%d: %s" % (i, dh[i]))
 
     @skip_doctest
     @line_magic
     def sc(self, parameter_s=''):
         """Shell capture - run shell command and capture output (DEPRECATED use !).
 
         DEPRECATED. Suboptimal, retained for backwards compatibility.
 
         You should use the form 'var = !command' instead. Example:
 
          "%sc -l myfiles = ls ~" should now be written as
 
          "myfiles = !ls ~"
 
         myfiles.s, myfiles.l and myfiles.n still apply as documented
         below.
 
         --
         %sc [options] varname=command
 
         IPython will run the given command using commands.getoutput(), and
         will then update the user's interactive namespace with a variable
         called varname, containing the value of the call.  Your command can
         contain shell wildcards, pipes, etc.
 
         The '=' sign in the syntax is mandatory, and the variable name you
         supply must follow Python's standard conventions for valid names.
 
         (A special format without variable name exists for internal use)
 
         Options:
 
           -l: list output.  Split the output on newlines into a list before
           assigning it to the given variable.  By default the output is stored
           as a single string.
 
           -v: verbose.  Print the contents of the variable.
 
         In most cases you should not need to split as a list, because the
         returned value is a special type of string which can automatically
         provide its contents either as a list (split on newlines) or as a
         space-separated string.  These are convenient, respectively, either
         for sequential processing or to be passed to a shell command.
 
         For example::
 
             # Capture into variable a
             In [1]: sc a=ls *py
 
             # a is a string with embedded newlines
             In [2]: a
             Out[2]: 'setup.py\\nwin32_manual_post_install.py'
 
             # which can be seen as a list:
             In [3]: a.l
             Out[3]: ['setup.py', 'win32_manual_post_install.py']
 
             # or as a whitespace-separated string:
             In [4]: a.s
             Out[4]: 'setup.py win32_manual_post_install.py'
 
             # a.s is useful to pass as a single command line:
             In [5]: !wc -l $a.s
               146 setup.py
               130 win32_manual_post_install.py
               276 total
 
             # while the list form is useful to loop over:
             In [6]: for f in a.l:
               ...:      !wc -l $f
               ...:
             146 setup.py
             130 win32_manual_post_install.py
 
         Similarly, the lists returned by the -l option are also special, in
         the sense that you can equally invoke the .s attribute on them to
         automatically get a whitespace-separated string from their contents::
 
             In [7]: sc -l b=ls *py
 
             In [8]: b
             Out[8]: ['setup.py', 'win32_manual_post_install.py']
 
             In [9]: b.s
             Out[9]: 'setup.py win32_manual_post_install.py'
 
         In summary, both the lists and strings used for output capture have
         the following special attributes::
 
             .l (or .list) : value as list.
             .n (or .nlstr): value as newline-separated string.
             .s (or .spstr): value as space-separated string.
         """
 
         opts,args = self.parse_options(parameter_s, 'lv')
         # Try to get a variable name and command to run
         try:
             # the variable name must be obtained from the parse_options
             # output, which uses shlex.split to strip options out.
             var,_ = args.split('=', 1)
             var = var.strip()
             # But the command has to be extracted from the original input
             # parameter_s, not on what parse_options returns, to avoid the
             # quote stripping which shlex.split performs on it.
             _,cmd = parameter_s.split('=', 1)
         except ValueError:
             var,cmd = '',''
         # If all looks ok, proceed
         split = 'l' in opts
         out = self.shell.getoutput(cmd, split=split)
         if 'v' in opts:
             print('%s ==\n%s' % (var, pformat(out)))
         if var:
             self.shell.user_ns.update({var:out})
         else:
             return out
 
     @line_cell_magic
     def sx(self, line='', cell=None):
         """Shell execute - run shell command and capture output (!! is short-hand).
 
         %sx command
 
         IPython will run the given command using commands.getoutput(), and
         return the result formatted as a list (split on '\\n').  Since the
         output is _returned_, it will be stored in ipython's regular output
         cache Out[N] and in the '_N' automatic variables.
 
         Notes:
 
         1) If an input line begins with '!!', then %sx is automatically
         invoked.  That is, while::
 
           !ls
 
         causes ipython to simply issue system('ls'), typing::
 
           !!ls
 
         is a shorthand equivalent to::
 
           %sx ls
 
         2) %sx differs from %sc in that %sx automatically splits into a list,
         like '%sc -l'.  The reason for this is to make it as easy as possible
         to process line-oriented shell output via further python commands.
         %sc is meant to provide much finer control, but requires more
         typing.
 
         3) Just like %sc -l, this is a list with special attributes:
         ::
 
           .l (or .list) : value as list.
           .n (or .nlstr): value as newline-separated string.
           .s (or .spstr): value as whitespace-separated string.
 
         This is very useful when trying to use such lists as arguments to
         system commands."""
         
         if cell is None:
             # line magic
             return self.shell.getoutput(line)
         else:
             opts,args = self.parse_options(line, '', 'out=')
             output = self.shell.getoutput(cell)
             out_name = opts.get('out', opts.get('o'))
             if out_name:
                 self.shell.user_ns[out_name] = output
             else:
                 return output
 
     system = line_cell_magic('system')(sx)
     bang = cell_magic('!')(sx)
 
     @line_magic
     def bookmark(self, parameter_s=''):
         """Manage IPython's bookmark system.
 
         %bookmark <name>       - set bookmark to current dir
         %bookmark <name> <dir> - set bookmark to <dir>
         %bookmark -l           - list all bookmarks
         %bookmark -d <name>    - remove bookmark
         %bookmark -r           - remove all bookmarks
 
         You can later on access a bookmarked folder with::
 
           %cd -b <name>
 
         or simply '%cd <name>' if there is no directory called <name> AND
         there is such a bookmark defined.
 
         Your bookmarks persist through IPython sessions, but they are
         associated with each profile."""
 
         opts,args = self.parse_options(parameter_s,'drl',mode='list')
         if len(args) > 2:
             raise UsageError("%bookmark: too many arguments")
 
         bkms = self.shell.db.get('bookmarks',{})
 
         if 'd' in opts:
             try:
                 todel = args[0]
             except IndexError:
                 raise UsageError(
                     "%bookmark -d: must provide a bookmark to delete")
             else:
                 try:
                     del bkms[todel]
                 except KeyError:
                     raise UsageError(
                         "%%bookmark -d: Can't delete bookmark '%s'" % todel)
 
         elif 'r' in opts:
             bkms = {}
         elif 'l' in opts:
             bks = sorted(bkms)
             if bks:
                 size = max(map(len, bks))
             else:
                 size = 0
             fmt = '%-'+str(size)+'s -> %s'
             print('Current bookmarks:')
             for bk in bks:
                 print(fmt % (bk, bkms[bk]))
         else:
             if not args:
                 raise UsageError("%bookmark: You must specify the bookmark name")
             elif len(args)==1:
                 bkms[args[0]] = os.getcwd()
             elif len(args)==2:
                 bkms[args[0]] = args[1]
         self.shell.db['bookmarks'] = bkms
 
     @line_magic
     def pycat(self, parameter_s=''):
         """Show a syntax-highlighted file through a pager.
 
         This magic is similar to the cat utility, but it will assume the file
         to be Python source and will show it with syntax highlighting.
 
         This magic command can either take a local filename, an url,
         an history range (see %history) or a macro as argument ::
 
         %pycat myscript.py
         %pycat 7-27
         %pycat myMacro
         %pycat http://www.example.com/myscript.py
         """
         if not parameter_s:
             raise UsageError('Missing filename, URL, input history range, '
                              'or macro.')
 
         try :
             cont = self.shell.find_user_code(parameter_s, skip_encoding_cookie=False)
         except (ValueError, IOError):
             print("Error: no such file, variable, URL, history range or macro")
             return
 
         page.page(self.shell.pycolorize(source_to_unicode(cont)))
 
     @magic_arguments.magic_arguments()
     @magic_arguments.argument(
         '-a', '--append', action='store_true', default=False,
         help='Append contents of the cell to an existing file. '
              'The file will be created if it does not exist.'
     )
     @magic_arguments.argument(
         'filename', type=str,
         help='file to write'
     )
     @cell_magic
     def writefile(self, line, cell):
         """Write the contents of the cell to a file.
         
         The file will be overwritten unless the -a (--append) flag is specified.
         """
         args = magic_arguments.parse_argstring(self.writefile, line)
         filename = os.path.expanduser(args.filename)
 
         if os.path.exists(filename):
             if args.append:
                 print("Appending to %s" % filename)
             else:
                 print("Overwriting %s" % filename)
         else:
             print("Writing %s" % filename)
         
         mode = 'a' if args.append else 'w'
         with io.open(filename, mode, encoding='utf-8') as f:
             f.write(cell)

IPython/core/profileapp.py

@@ -1,312 +1,307 b''
 # encoding: utf-8
 """
 An application for managing IPython profiles.
 
 To be invoked as the `ipython profile` subcommand.
 
 Authors:
 
 * Min RK
 
 """
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2008  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.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 import os
 
 from traitlets.config.application import Application
 from IPython.core.application import (
     BaseIPythonApplication, base_flags
 )
 from IPython.core.profiledir import ProfileDir
 from IPython.utils.importstring import import_item
 from IPython.paths import get_ipython_dir, get_ipython_package_dir
 from traitlets import Unicode, Bool, Dict, observe
 
 #-----------------------------------------------------------------------------
 # Constants
 #-----------------------------------------------------------------------------
 
 create_help = """Create an IPython profile by name
 
 Create an ipython profile directory by its name or
 profile directory path. Profile directories contain
 configuration, log and security related files and are named
 using the convention 'profile_<name>'. By default they are
 located in your ipython directory. Once created, you will
 can edit the configuration files in the profile
 directory to configure IPython. Most users will create a
 profile directory by name,
 `ipython profile create myprofile`, which will put the directory
 in `<ipython_dir>/profile_myprofile`.
 """
 list_help = """List available IPython profiles
 
 List all available profiles, by profile location, that can
 be found in the current working directly or in the ipython
 directory. Profile directories are named using the convention
 'profile_<profile>'.
 """
 profile_help = """Manage IPython profiles
 
 Profile directories contain
 configuration, log and security related files and are named
 using the convention 'profile_<name>'. By default they are
 located in your ipython directory.  You can create profiles
 with `ipython profile create <name>`, or see the profiles you
 already have with `ipython profile list`
 
 To get started configuring IPython, simply do:
 
 $> ipython profile create
 
 and IPython will create the default profile in <ipython_dir>/profile_default,
 where you can edit ipython_config.py to start configuring IPython.
 
 """
 
 _list_examples = "ipython profile list  # list all profiles"
 
 _create_examples = """
 ipython profile create foo         # create profile foo w/ default config files
 ipython profile create foo --reset # restage default config files over current
 ipython profile create foo --parallel # also stage parallel config files
 """
 
 _main_examples = """
 ipython profile create -h  # show the help string for the create subcommand
 ipython profile list -h    # show the help string for the list subcommand
 
 ipython locate profile foo # print the path to the directory for profile 'foo'
 """
 
 #-----------------------------------------------------------------------------
 # Profile Application Class (for `ipython profile` subcommand)
 #-----------------------------------------------------------------------------
 
 
 def list_profiles_in(path):
     """list profiles in a given root directory"""
-    files = os.listdir(path)
     profiles = []
-    for f in files:
-        try:
-            full_path = os.path.join(path, f)
-        except UnicodeError:
-            continue
-        if os.path.isdir(full_path) and f.startswith('profile_'):
-            profiles.append(f.split('_',1)[-1])
+    with os.scandir(path) as files:
+        for f in files:
+            if f.is_dir() and f.name.startswith('profile_'):
+                profiles.append(f.name.split('_', 1)[-1])
     return profiles
 
 
 def list_bundled_profiles():
     """list profiles that are bundled with IPython."""
     path = os.path.join(get_ipython_package_dir(), u'core', u'profile')
-    files = os.listdir(path)
     profiles = []
-    for profile in files:
-        full_path = os.path.join(path, profile)
-        if os.path.isdir(full_path) and profile != "__pycache__":
-            profiles.append(profile)
+    with os.scandir(path) as files:
+        for profile in files:
+            if profile.is_dir() and profile.name != "__pycache__":
+                profiles.append(profile.name)
     return profiles
 
 
 class ProfileLocate(BaseIPythonApplication):
     description = """print the path to an IPython profile dir"""
     
     def parse_command_line(self, argv=None):
         super(ProfileLocate, self).parse_command_line(argv)
         if self.extra_args:
             self.profile = self.extra_args[0]
     
     def start(self):
         print(self.profile_dir.location)
 
 
 class ProfileList(Application):
     name = u'ipython-profile'
     description = list_help
     examples = _list_examples
 
     aliases = Dict({
         'ipython-dir' : 'ProfileList.ipython_dir',
         'log-level' : 'Application.log_level',
     })
     flags = Dict(dict(
         debug = ({'Application' : {'log_level' : 0}},
             "Set Application.log_level to 0, maximizing log output."
         )
     ))
 
     ipython_dir = Unicode(get_ipython_dir(),
         help="""
         The name of the IPython directory. This directory is used for logging
         configuration (through profiles), history storage, etc. The default
         is usually $HOME/.ipython. This options can also be specified through
         the environment variable IPYTHONDIR.
         """
     ).tag(config=True)
 
 
     def _print_profiles(self, profiles):
         """print list of profiles, indented."""
         for profile in profiles:
             print('    %s' % profile)
 
     def list_profile_dirs(self):
         profiles = list_bundled_profiles()
         if profiles:
             print()
             print("Available profiles in IPython:")
             self._print_profiles(profiles)
             print()
             print("    The first request for a bundled profile will copy it")
             print("    into your IPython directory (%s)," % self.ipython_dir)
             print("    where you can customize it.")
         
         profiles = list_profiles_in(self.ipython_dir)
         if profiles:
             print()
             print("Available profiles in %s:" % self.ipython_dir)
             self._print_profiles(profiles)
         
         profiles = list_profiles_in(os.getcwd())
         if profiles:
             print()
             print("Available profiles in current directory (%s):" % os.getcwd())
             self._print_profiles(profiles)
         
         print()
         print("To use any of the above profiles, start IPython with:")
         print("    ipython --profile=<name>")
         print()
 
     def start(self):
         self.list_profile_dirs()
 
 
 create_flags = {}
 create_flags.update(base_flags)
 # don't include '--init' flag, which implies running profile create in other apps
 create_flags.pop('init')
 create_flags['reset'] = ({'ProfileCreate': {'overwrite' : True}},
                         "reset config files in this profile to the defaults.")
 create_flags['parallel'] = ({'ProfileCreate': {'parallel' : True}},
                         "Include the config files for parallel "
                         "computing apps (ipengine, ipcontroller, etc.)")
 
 
 class ProfileCreate(BaseIPythonApplication):
     name = u'ipython-profile'
     description = create_help
     examples = _create_examples
     auto_create = Bool(True)
     def _log_format_default(self):
         return "[%(name)s] %(message)s"
 
     def _copy_config_files_default(self):
         return True
 
     parallel = Bool(False,
         help="whether to include parallel computing config files"
     ).tag(config=True)
 
     @observe('parallel')
     def _parallel_changed(self, change):
         parallel_files = [   'ipcontroller_config.py',
                             'ipengine_config.py',
                             'ipcluster_config.py'
                         ]
         if change['new']:
             for cf in parallel_files:
                 self.config_files.append(cf)
         else:
             for cf in parallel_files:
                 if cf in self.config_files:
                     self.config_files.remove(cf)
 
     def parse_command_line(self, argv):
         super(ProfileCreate, self).parse_command_line(argv)
         # accept positional arg as profile name
         if self.extra_args:
             self.profile = self.extra_args[0]
 
     flags = Dict(create_flags)
 
     classes = [ProfileDir]
     
     def _import_app(self, app_path):
         """import an app class"""
         app = None
         name = app_path.rsplit('.', 1)[-1]
         try:
             app = import_item(app_path)
         except ImportError:
             self.log.info("Couldn't import %s, config file will be excluded", name)
         except Exception:
             self.log.warning('Unexpected error importing %s', name, exc_info=True)
         return app
 
     def init_config_files(self):
         super(ProfileCreate, self).init_config_files()
         # use local imports, since these classes may import from here
         from IPython.terminal.ipapp import TerminalIPythonApp
         apps = [TerminalIPythonApp]
         for app_path in (
             'ipykernel.kernelapp.IPKernelApp',
         ):
             app = self._import_app(app_path)
             if app is not None:
                 apps.append(app)
         if self.parallel:
             from ipyparallel.apps.ipcontrollerapp import IPControllerApp
             from ipyparallel.apps.ipengineapp import IPEngineApp
             from ipyparallel.apps.ipclusterapp import IPClusterStart
             apps.extend([
                 IPControllerApp,
                 IPEngineApp,
                 IPClusterStart,
             ])
         for App in apps:
             app = App()
             app.config.update(self.config)
             app.log = self.log
             app.overwrite = self.overwrite
             app.copy_config_files=True
             app.ipython_dir=self.ipython_dir
             app.profile_dir=self.profile_dir
             app.init_config_files()
 
     def stage_default_config_file(self):
         pass
 
 
 class ProfileApp(Application):
     name = u'ipython profile'
     description = profile_help
     examples = _main_examples
 
     subcommands = Dict(dict(
         create = (ProfileCreate, ProfileCreate.description.splitlines()[0]),
         list = (ProfileList, ProfileList.description.splitlines()[0]),
         locate = (ProfileLocate, ProfileLocate.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()