Hi, On Tue, May 05, 2009 at 03:00:45AM -0700, Colin Gillespie wrote: > > Hi, > > I think that the expected behaviour would be for pow(x,2) to return > x^2, as opposed to a general function. Otherwise, it would be > inconsistent with how 'sin' and 'exp' are handled (for example). >
I also think the current behaviour is inconsistent and, what is more
important, counterintuitive for Python users. I attached a patch that
fixes this issue. It passes all tests when using py.test, but fails a
few tests with sympy's test(), e.g.:
sympy/integrals/tests/test_integrals.py[38] .............................E......
.. [FAIL]
sympy/integrals/tests/test_lineintegrals.py[1] . [OK]
sympy/integrals/tests/test_rationaltools.py[1] . [OK]
sympy/integrals/tests/test_risch.py[19] ........^C interrupted by user
________________________________________________________________________________
_________ sympy/integrals/tests/test_integrals.py:test_evalf_integrals _________
File "/home/matt/repo/git/sympy/sympy/integrals/tests/test_integrals.py",
line 255, in test_evalf_integrals
assert NS(pi - 4*Integral('sqrt(1-x**2)', (x, 0, 1)), 15, maxprec=30,
chop=True) in ('0.0', '0')
File "./sympy/integrals/integrals.py", line 20, in __new__
function = sympify(function)
File "./sympy/core/sympify.py", line 121, in sympify
return ast_parser.parse_expr(a, locals)
File "./sympy/core/ast_parser.py", line 96, in parse_expr
return eval(e, local_dict, global_dict)
File "<string>", line 1, in <module>
File "./sympy/galgebra/GA.py", line 1876, in __pow__
return(MV.outer_product(self,mv))
File "./sympy/galgebra/GA.py", line 1507, in outer_product
product = mv1.scalar_mul(mv2)
File "./sympy/galgebra/GA.py", line 1899, in scalar_mul
if isinstance(self.mv[i],numpy.ndarray):
IndexError: list index out of range
After removing galgebra/tests everything started to work fine. Any ideas
what is wrong here? (test(), py.test, galgebra/tests or something else?)
--
Mateusz
From c94d48872ca4b4054e30b40885d943f59f93c639 Mon Sep 17 00:00:00 2001
From: Mateusz Paprocki <matt...@gmail.com>
Date: Thu, 30 Apr 2009 19:26:17 +0200
Subject: [PATCH] Don't convert __builtin__ attribute to a Symbol
This patch makes:
sympify('pow(x, 2)')
return x**2 as opposed to Function('pow')(x, 2).
---
sympy/core/ast_parser.py | 5 ++++-
sympy/core/ast_parser_python24.py | 5 ++++-
sympy/core/tests/test_sympify.py | 4 ++++
3 files changed, 12 insertions(+), 2 deletions(-)
diff --git a/sympy/core/ast_parser.py b/sympy/core/ast_parser.py
index e633ab5..0f0e4c6 100644
--- a/sympy/core/ast_parser.py
+++ b/sympy/core/ast_parser.py
@@ -25,6 +25,8 @@
from sympy import Integer, Real, Basic
+import __builtin__
+
try:
import ast
ast_enabled = True
@@ -59,7 +61,7 @@ def visit_Name(self, node):
if isinstance(name_obj, (Basic, type)) or callable(name_obj):
return node
- elif node.id in ['True', 'False']:
+ elif hasattr(__builtin__, node.id):
return node
return fix_missing_locations(Call(Name('Symbol', Load()),
[Str(node.id)], [], None, None))
@@ -100,3 +102,4 @@ def parse_expr(s, local_dict):
return SymPyParser(local_dict=local_dict).parse_expr(s)
except SyntaxError:
raise SympifyError("sorry")
+
diff --git a/sympy/core/ast_parser_python24.py
b/sympy/core/ast_parser_python24.py
index ed7e41b..e4ef30b 100644
--- a/sympy/core/ast_parser_python24.py
+++ b/sympy/core/ast_parser_python24.py
@@ -8,6 +8,8 @@
from basic import Basic
from symbol import Symbol
+import __builtin__
+
_is_integer = re.compile(r'\A\d+(l|L)?\Z').match
class SymPyTransformer(Transformer):
@@ -42,7 +44,7 @@ def atom_name(self, nodelist):
if isinstance(name_obj, (Basic, type)) or callable(name_obj):
return Const(name_obj, lineno=lineno)
- elif name in ['True', 'False']:
+ elif hasattr(__builtin__, name):
return Const(eval(name), lineno=lineno)
symbol_obj = Symbol(name)
@@ -97,3 +99,4 @@ def parse_expr(self, ws_expression):
parsed_expr = eval(code, self.local_dict, self.global_dict) #Changed
order to prefer sympy objects to user defined
return parsed_expr
+
diff --git a/sympy/core/tests/test_sympify.py b/sympy/core/tests/test_sympify.py
index 63094f5..33749d2 100644
--- a/sympy/core/tests/test_sympify.py
+++ b/sympy/core/tests/test_sympify.py
@@ -60,6 +60,9 @@ def test_sympify_function():
assert sympify('factor(x**2-1, x)') == -(1-x)*(x+1)
assert sympify('sin(pi/2)*cos(pi)') == -Integer(1)
+def test_builtin():
+ assert sympify('pow(x, 2)') == x**2
+
def test_sympify_poly():
p = Poly(x**2+x+1, x)
@@ -245,3 +248,4 @@ def test_issue883():
def test_S_sympify():
assert S(1)/2 == sympify(1)/2
assert (-2)**(S(1)/2) == sqrt(2)*I
+
--
1.6.2.3
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