This is now independent from objects and out of the core. Assume is
the basic object is this new model, and it is only a container
(all logic is done by sympy.logic and sympy.queries).
---
sympy/__init__.py | 2 +-
sympy/assumptions/__init__.py | 2 +
sympy/assumptions/assume.py | 97 +++++++++++++++++++++++++
sympy/assumptions/tests/test_assumptions_2.py | 58 +++++++++++++++
sympy/printing/pretty/pretty.py | 3 +
5 files changed, 161 insertions(+), 1 deletions(-)
create mode 100644 sympy/assumptions/__init__.py
create mode 100644 sympy/assumptions/assume.py
create mode 100644 sympy/assumptions/tests/test_assumptions_2.py
diff --git a/sympy/__init__.py b/sympy/__init__.py
index 3be16a4..c813490 100644
--- a/sympy/__init__.py
+++ b/sympy/__init__.py
@@ -21,7 +21,7 @@ def __sympy_debug():
import symbol as stdlib_symbol
from sympy.core import *
-
+from assumptions import *
from polys import *
from series import *
from functions import *
diff --git a/sympy/assumptions/__init__.py b/sympy/assumptions/__init__.py
new file mode 100644
index 0000000..bdd47c2
--- /dev/null
+++ b/sympy/assumptions/__init__.py
@@ -0,0 +1,2 @@
+from assume import Assume, register_global_assumptions,
list_global_assumptions, \
+ remove_global_assumptions, clean_global_assumptions
diff --git a/sympy/assumptions/assume.py b/sympy/assumptions/assume.py
new file mode 100644
index 0000000..4069ee9
--- /dev/null
+++ b/sympy/assumptions/assume.py
@@ -0,0 +1,97 @@
+# doctests are disabled because of issue #1521
+from sympy.core import Basic, Symbol
+from sympy.core.relational import Relational
+
+__global_assumptions = []
+
+def register_global_assumptions(*assump):
+ """Register an assumption as global
+
+ Examples:
+# >>> from sympy import *
+# >>> list_global()
+# []
+# >>> x = Symbol('x')
+# >>> register_global(Assume(x, real=True))
+# True
+# >>> list_global()
+# [Assume(x, real=True)]
+
+ You can undo this calling remove_global
+ """
+ __global_assumptions.extend(assump)
+
+def list_global_assumptions():
+ """List all global assumptions"""
+ return __global_assumptions[:] # make a copy
+
+def remove_global_assumptions(*assump):
+ """Remove a global assumption. If argument is not
+ a global assumption, it will raise ValueError
+ """
+ for assumption in assump:
+ __global_assumptions.remove(assumption)
+
+def clean_global_assumptions():
+ """Remove all global assumptions"""
+ global __global_assumptions
+ __global_assumptions = []
+
+class Assume(Basic):
+ """New-style assumptions
+
+# >>> from sympy import Symbol, Assume
+# >>> x = Symbol('x')
+# >>> Assume(x, integer=True)
+# Assume( x, integer = True )
+# >>> Assume(x, integer=False)
+# Assume( x, integer = False )
+# >>> Assume( x > 1 )
+# Assume( x > 1, relational = True)
+ """
+
+ def __init__(self, expr, *args, **kwargs):
+ if isinstance(expr, Symbol):
+ key, value = kwargs.popitem()
+ elif isinstance(expr, Relational):
+ key, value = 'relational', True
+ if kwargs:
+ raise ValueError('Wrong set of arguments')
+ self._args = (expr, key, value)
+
+ is_Atom = True # do not attempt to decompose this
+
+ @property
+ def expr(self):
+ return self._args[0]
+
+ @property
+ def key(self):
+ return self._args[1]
+
+ @property
+ def value(self):
+ return self._args[2]
+
+ def __eq__(self, other):
+ if type(other) == Assume:
+ return self._args == other._args
+ return False
+
+def eliminate_assume(expr, symbol=None):
+ """
+ Will convert an expression with assumptions to an equivalent with all
assumptions
+ replaced by symbols
+ Assume(x, integer=True) --> integer
+ Assume(x, integer=False) --> ~integer
+ """
+ if type(expr) == Assume:
+ if symbol is not None:
+ if not expr.expr.has(symbol): return
+ if expr.value: return Symbol(expr.key)
+ return ~Symbol(expr.key)
+ args = []
+ for a in expr.args:
+ args.append(eliminate_assume(a))
+ return type(expr)(*args)
+
diff --git a/sympy/assumptions/tests/test_assumptions_2.py
b/sympy/assumptions/tests/test_assumptions_2.py
new file mode 100644
index 0000000..d95162f
--- /dev/null
+++ b/sympy/assumptions/tests/test_assumptions_2.py
@@ -0,0 +1,58 @@
+"""rename this to test_assumptions.py when the old assumptions system is
deleted"""
+from sympy.core import symbols
+from sympy.assumptions import Assume, register_global_assumptions, \
+ list_global_assumptions, remove_global_assumptions,
clean_global_assumptions
+from sympy.assumptions.assume import eliminate_assume
+from sympy.printing import pretty
+
+def test_assume():
+ x = symbols('x')
+ assump = Assume(x, integer=True)
+ assert assump.expr == x
+ assert assump.key == 'integer'
+ assert assump.value == True
+
+def test_False():
+ """Test Assume object with False keys"""
+ x = symbols('x')
+ assump = Assume(x, integer=False)
+ assert assump.expr == x
+ assert assump.key == 'integer'
+ assert assump.value == False
+
+def test_equal():
+ """Test for equality"""
+ x = symbols('x')
+ assert Assume(x, positive=True) == Assume(x, positive=True)
+ assert Assume(x, positive=True) != Assume(x, positive=False)
+ assert Assume(x, positive=False) == Assume(x, positive=False)
+
+def test_pretty():
+ x = symbols('x')
+ assert pretty(Assume(x, positive=True)) == 'Assume(x, positive=True)'
+
+def test_eliminate_assumptions():
+ a, b, x, y = symbols('abxy')
+ assert eliminate_assume(Assume(x, a=True)) == a
+ assert eliminate_assume(Assume(x, a=True), symbol=x) == a
+ assert eliminate_assume(Assume(x, a=True), symbol=y) == None
+ assert eliminate_assume(Assume(x, a=False)) == ~a
+ assert eliminate_assume(Assume(x, a=False), symbol=y) == None
+ assert eliminate_assume(Assume(x, a=True) | Assume(x, b=True)) == a | b
+ assert eliminate_assume(Assume(x, a=True) | Assume(x, b=False)) == a | ~b
+
+def test_global():
+ """Test for global assumptions"""
+ x, y = symbols('x y')
+ register_global_assumptions(Assume(x>0))
+ assert Assume(x>0) in list_global_assumptions()
+ remove_global_assumptions(Assume(x>0))
+ assert (Assume(x>0) in list_global_assumptions()) == False
+
+ # same with multiple of assumptions
+ register_global_assumptions(Assume(x>0), Assume(y>0))
+ assert Assume(x>0) in list_global_assumptions()
+ assert Assume(y>0) in list_global_assumptions()
+ clean_global_assumptions()
+ assert (Assume(x>0) in list_global_assumptions()) == False
+ assert (Assume(y>0) in list_global_assumptions()) == False
diff --git a/sympy/printing/pretty/pretty.py b/sympy/printing/pretty/pretty.py
index 19ffff2..6d7f4da 100644
--- a/sympy/printing/pretty/pretty.py
+++ b/sympy/printing/pretty/pretty.py
@@ -56,6 +56,9 @@ def _print_Atom(self, e):
except KeyError:
return self.emptyPrinter(e)
+ def _print_Assume(self, e):
+ return prettyForm("Assume(%s, %s=%s)" % (e.expr, e.key, e.value))
+
# Infinity inherits from Rational, so we have to override _print_XXX order
_print_Infinity = _print_Atom
_print_NegativeInfinity = _print_Atom
--
1.6.2.2
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