Interface to Sage#

This is an expect interface to another copy of the Sage interpreter.

class sage.interfaces.sage0.Sage(logfile=None, preparse=True, python=False, init_code=None, server=None, server_tmpdir=None, remote_cleaner=True, **kwds)[source]#

Bases: ExtraTabCompletion, Expect

Expect interface to the Sage interpreter itself.

INPUT:

  • server – (optional); if specified runs Sage on a remote machine with address. You must have ssh keys setup so you can login to the remote machine by typing “ssh remote_machine” and no password, call _install_hints_ssh() for hints on how to do that.

The version of Sage should be the same as on the local machine, since pickling is used to move data between the two Sage process.

EXAMPLES: We create an interface to a copy of Sage. This copy of Sage runs as an external process with its own memory space, etc.

sage: s = Sage()

>>> from sage.all import *
>>> s = Sage()

Create the element 2 in our new copy of Sage, and cube it.

sage: a = s(2)
sage: a^3
8

>>> from sage.all import *
>>> a = s(Integer(2))
>>> a**Integer(3)
8

Create a vector space of dimension \(4\), and compute its generators:

sage: V = s('QQ^4')
sage: V.gens()
((1, 0, 0, 0), (0, 1, 0, 0), (0, 0, 1, 0), (0, 0, 0, 1))

>>> from sage.all import *
>>> V = s('QQ^4')
>>> V.gens()
((1, 0, 0, 0), (0, 1, 0, 0), (0, 0, 1, 0), (0, 0, 0, 1))

Note that V is a not a vector space, it’s a wrapper around an object (which happens to be a vector space), in another running instance of Sage.

sage: type(V)
<class 'sage.interfaces.sage0.SageElement'>
sage: V.parent()
Sage
sage: g = V.0;  g
(1, 0, 0, 0)
sage: g.parent()
Sage

>>> from sage.all import *
>>> type(V)
<class 'sage.interfaces.sage0.SageElement'>
>>> V.parent()
Sage
>>> g = V.gen(0);  g
(1, 0, 0, 0)
>>> g.parent()
Sage

We can still get the actual parent by using the name attribute of g, which is the variable name of the object in the child process.

sage: s('%s.parent()' % g.name())
Vector space of dimension 4 over Rational Field

>>> from sage.all import *
>>> s('%s.parent()' % g.name())
Vector space of dimension 4 over Rational Field

Note that the memory space is completely different.

sage: x = 10
sage: s('x = 5')
5
sage: x
10
sage: s('x')
5

>>> from sage.all import *
>>> x = Integer(10)
>>> s('x = 5')
5
>>> x
10
>>> s('x')
5

We can have the child interpreter itself make another child Sage process, so now three copies of Sage are running:

sage: s3 = s('Sage()')
sage: a = s3(10)
sage: a
10

>>> from sage.all import *
>>> s3 = s('Sage()')
>>> a = s3(Integer(10))
>>> a
10

This \(a=10\) is in a subprocess of a subprocess of your original Sage.

sage: _ = s.eval('%s.eval("x=8")' % s3.name())
sage: s3('"x"')
8
sage: s('x')
5
sage: x
10

>>> from sage.all import *
>>> _ = s.eval('%s.eval("x=8")' % s3.name())
>>> s3('"x"')
8
>>> s('x')
5
>>> x
10

The double quotes are needed because the call to s3 first evaluates its arguments using the s interpreter, so the call to s3 is passed s('"x"'), which is the string "x" in the s interpreter.

clear(var)[source]#

Clear the variable named var.

Note that the exact format of the NameError for a cleared variable is slightly platform dependent, see Issue #10539.

EXAMPLES:

sage: sage0.set('x', '2')
sage: sage0.get('x')
'2'
sage: sage0.clear('x')
sage: 'NameError' in sage0.get('x')
True

>>> from sage.all import *
>>> sage0.set('x', '2')
>>> sage0.get('x')
'2'
>>> sage0.clear('x')
>>> 'NameError' in sage0.get('x')
True
console()[source]#

Spawn a new Sage command-line session.

EXAMPLES:

sage: sage0.console() #not tested
----------------------------------------------------------------------
| SageMath version ..., Release Date: ...                            |
| Using Python ....   Type "help()" for help.                        |
----------------------------------------------------------------------
...

>>> from sage.all import *
>>> sage0.console() #not tested
----------------------------------------------------------------------
| SageMath version ..., Release Date: ...                            |
| Using Python ....   Type "help()" for help.                        |
----------------------------------------------------------------------
...
cputime(t=None)[source]#

Return cputime since this Sage subprocess was started.

EXAMPLES:

sage: sage0.cputime()     # random output
1.3530439999999999
sage: sage0('factor(2^157-1)')
852133201 * 60726444167 * 1654058017289 * 2134387368610417
sage: sage0.cputime()     # random output
1.6462939999999999

>>> from sage.all import *
>>> sage0.cputime()     # random output
1.3530439999999999
>>> sage0('factor(2^157-1)')
852133201 * 60726444167 * 1654058017289 * 2134387368610417
>>> sage0.cputime()     # random output
1.6462939999999999
eval(line, strip=True, **kwds)[source]#

Send the code x to a second instance of the Sage interpreter and return the output as a string.

This allows you to run two completely independent copies of Sage at the same time in a unified way.

INPUT:

  • line – input line of code

  • strip – ignored

EXAMPLES:

sage: sage0.eval('2+2')
'4'

>>> from sage.all import *
>>> sage0.eval('2+2')
'4'
get(var)[source]#

Get the value of the variable var.

EXAMPLES:

sage: sage0.set('x', '2')
sage: sage0.get('x')
'2'

>>> from sage.all import *
>>> sage0.set('x', '2')
>>> sage0.get('x')
'2'
new(x)[source]#

EXAMPLES:

sage: sage0.new(2)
2
sage: _.parent()
Sage

>>> from sage.all import *
>>> sage0.new(Integer(2))
2
>>> _.parent()
Sage
preparse(x)[source]#

Returns the preparsed version of the string s.

EXAMPLES:

sage: sage0.preparse('2+2')
'Integer(2)+Integer(2)'

>>> from sage.all import *
>>> sage0.preparse('2+2')
'Integer(2)+Integer(2)'
set(var, value)[source]#

Set the variable var to the given value.

EXAMPLES:

sage: sage0.set('x', '2')
sage: sage0.get('x')
'2'

>>> from sage.all import *
>>> sage0.set('x', '2')
>>> sage0.get('x')
'2'
version()[source]#

EXAMPLES:

sage: sage0.version()
'SageMath version ..., Release Date: ...'
sage: sage0.version() == version()
True

>>> from sage.all import *
>>> sage0.version()
'SageMath version ..., Release Date: ...'
>>> sage0.version() == version()
True
class sage.interfaces.sage0.SageElement(parent, value, is_name=False, name=None)[source]#

Bases: ExpectElement

class sage.interfaces.sage0.SageFunction(obj, name)[source]#

Bases: FunctionElement

sage.interfaces.sage0.reduce_load_Sage()[source]#

EXAMPLES:

sage: from sage.interfaces.sage0 import reduce_load_Sage
sage: reduce_load_Sage()
Sage

>>> from sage.all import *
>>> from sage.interfaces.sage0 import reduce_load_Sage
>>> reduce_load_Sage()
Sage
sage.interfaces.sage0.reduce_load_element(s)[source]#

EXAMPLES:

sage: from sage.interfaces.sage0 import reduce_load_element
sage: s = dumps(1/2)
sage: half = reduce_load_element(s); half
1/2
sage: half.parent()
Sage

>>> from sage.all import *
>>> from sage.interfaces.sage0 import reduce_load_element
>>> s = dumps(Integer(1)/Integer(2))
>>> half = reduce_load_element(s); half
1/2
>>> half.parent()
Sage
sage.interfaces.sage0.sage0_console()[source]#

Spawn a new Sage command-line session.

EXAMPLES:

sage: sage0_console() #not tested
----------------------------------------------------------------------
| SageMath version ..., Release Date: ...                            |
| Using Python ....   Type "help()" for help.                        |
----------------------------------------------------------------------
...

>>> from sage.all import *
>>> sage0_console() #not tested
----------------------------------------------------------------------
| SageMath version ..., Release Date: ...                            |
| Using Python ....   Type "help()" for help.                        |
----------------------------------------------------------------------
...
sage.interfaces.sage0.sage0_version()[source]#

EXAMPLES:

sage: from sage.interfaces.sage0 import sage0_version
sage: sage0_version() == version()
True

>>> from sage.all import *
>>> from sage.interfaces.sage0 import sage0_version
>>> sage0_version() == version()
True