Warning

This documentation covers a development version of IPython. The development version may differ significantly from the latest stable release.

Important

This documentation covers IPython versions 6.0 and higher. Beginning with version 6.0, IPython stopped supporting compatibility with Python versions lower than 3.3 including all versions of Python 2.7.

If you are looking for an IPython version compatible with Python 2.7, please use the IPython 5.x LTS release and refer to its documentation (LTS is the long term support release).

Module: `core.magics.osm`¶

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.

1 Class¶

class IPython.core.magics.osm.OSMagics(**kwargs: Any)¶

Bases: Magics

Magics to interact with the underlying OS (shell-type functionality).

__init__(shell=None, **kwargs)¶

Create a configurable given a config config.

Parameters:

config (Config) – If this is empty, default values are used. If config is a Config instance, it will be used to configure the instance.
parent (Configurable instance, optional) – The parent Configurable instance of this object.

Notes

Subclasses of Configurable must call the __init__() method of Configurable before doing anything else and using super():

class MyConfigurable(Configurable):
    def __init__(self, config=None):
        super(MyConfigurable, self).__init__(config=config)
        # Then any other code you need to finish initialization.

This ensures that instances will be configured properly.

alias(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: https://peps.python.org/pep-0215/. 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'>

bang(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.

bookmark(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.

cd(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

Hitting a tab key after cd -b allows you to tab-complete bookmark names.

Note

cd <bookmark_name> is enough if there is no directory <bookmark_name>, but a bookmark with the name exists.

Options:

-q: Be 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

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

cd_force_quiet¶: Force %cd magic to be quiet even if -q is not passed.

dhist(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>.

dirs(parameter_s='')¶: Return the current directory stack.

env(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

isexec(file)¶: Test for executable file on non POSIX system

popd(parameter_s='')¶: Change to directory popped off the top of the stack.

pushd(parameter_s='')¶

Place the current dir on stack and change directory.

Usage:: %pushd [‘dirname’]

pwd(parameter_s='')¶

Return the current working directory path.

Examples

In [9]: pwd
Out[9]: '/home/tsuser/sprint/ipython'

pycat(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.

If no parameter is given, prints out history of current session up to this point.

%pycat myscript.py
%pycat 7-27
%pycat myMacro
%pycat http://www.example.com/myscript.py

rehashx(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.

sc(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.

set_env(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

sx(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.

system(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.

unalias(parameter_s='')¶: Remove an alias

writefile(line, cell)¶

%writefile [-a] filename

Write the contents of the cell to a file.

The file will be overwritten unless the -a (–append) flag is specified.

positional arguments:

filename file to write

options:

-a, --append: Append contents of the cell to an existing file. The file will be created if it does not exist.

Module: core.magics.osm¶

1 Class¶

Module: `core.magics.osm`¶