Current File : //usr/lib/python3/dist-packages/sympy/printing/tests/test_lambdarepr.py
from sympy import symbols, sin, Matrix, Interval, Piecewise, Sum, lambdify, \
Expr, sqrt
from sympy.testing.pytest import raises
from sympy.printing.tensorflow import TensorflowPrinter
from sympy.printing.lambdarepr import lambdarepr, LambdaPrinter, NumExprPrinter
x, y, z = symbols("x,y,z")
i, a, b = symbols("i,a,b")
j, c, d = symbols("j,c,d")
def test_basic():
assert lambdarepr(x*y) == "x*y"
assert lambdarepr(x + y) in ["y + x", "x + y"]
assert lambdarepr(x**y) == "x**y"
def test_matrix():
A = Matrix([[x, y], [y*x, z**2]])
# assert lambdarepr(A) == "ImmutableDenseMatrix([[x, y], [x*y, z**2]])"
# Test printing a Matrix that has an element that is printed differently
# with the LambdaPrinter than in the StrPrinter.
p = Piecewise((x, True), evaluate=False)
A = Matrix([p])
assert lambdarepr(A) == "ImmutableDenseMatrix([[((x))]])"
def test_piecewise():
# In each case, test eval() the lambdarepr() to make sure there are a
# correct number of parentheses. It will give a SyntaxError if there aren't.
h = "lambda x: "
p = Piecewise((x, True), evaluate=False)
l = lambdarepr(p)
eval(h + l)
assert l == "((x))"
p = Piecewise((x, x < 0))
l = lambdarepr(p)
eval(h + l)
assert l == "((x) if (x < 0) else None)"
p = Piecewise(
(1, x < 1),
(2, x < 2),
(0, True)
)
l = lambdarepr(p)
eval(h + l)
assert l == "((1) if (x < 1) else (2) if (x < 2) else (0))"
p = Piecewise(
(1, x < 1),
(2, x < 2),
)
l = lambdarepr(p)
eval(h + l)
assert l == "((1) if (x < 1) else (2) if (x < 2) else None)"
p = Piecewise(
(x, x < 1),
(x**2, Interval(3, 4, True, False).contains(x)),
(0, True),
)
l = lambdarepr(p)
eval(h + l)
assert l == "((x) if (x < 1) else (x**2) if (((x <= 4)) and ((x > 3))) else (0))"
p = Piecewise(
(x**2, x < 0),
(x, x < 1),
(2 - x, x >= 1),
(0, True), evaluate=False
)
l = lambdarepr(p)
eval(h + l)
assert l == "((x**2) if (x < 0) else (x) if (x < 1)"\
" else (2 - x) if (x >= 1) else (0))"
p = Piecewise(
(x**2, x < 0),
(x, x < 1),
(2 - x, x >= 1), evaluate=False
)
l = lambdarepr(p)
eval(h + l)
assert l == "((x**2) if (x < 0) else (x) if (x < 1)"\
" else (2 - x) if (x >= 1) else None)"
p = Piecewise(
(1, x >= 1),
(2, x >= 2),
(3, x >= 3),
(4, x >= 4),
(5, x >= 5),
(6, True)
)
l = lambdarepr(p)
eval(h + l)
assert l == "((1) if (x >= 1) else (2) if (x >= 2) else (3) if (x >= 3)"\
" else (4) if (x >= 4) else (5) if (x >= 5) else (6))"
p = Piecewise(
(1, x <= 1),
(2, x <= 2),
(3, x <= 3),
(4, x <= 4),
(5, x <= 5),
(6, True)
)
l = lambdarepr(p)
eval(h + l)
assert l == "((1) if (x <= 1) else (2) if (x <= 2) else (3) if (x <= 3)"\
" else (4) if (x <= 4) else (5) if (x <= 5) else (6))"
p = Piecewise(
(1, x > 1),
(2, x > 2),
(3, x > 3),
(4, x > 4),
(5, x > 5),
(6, True)
)
l = lambdarepr(p)
eval(h + l)
assert l =="((1) if (x > 1) else (2) if (x > 2) else (3) if (x > 3)"\
" else (4) if (x > 4) else (5) if (x > 5) else (6))"
p = Piecewise(
(1, x < 1),
(2, x < 2),
(3, x < 3),
(4, x < 4),
(5, x < 5),
(6, True)
)
l = lambdarepr(p)
eval(h + l)
assert l == "((1) if (x < 1) else (2) if (x < 2) else (3) if (x < 3)"\
" else (4) if (x < 4) else (5) if (x < 5) else (6))"
p = Piecewise(
(Piecewise(
(1, x > 0),
(2, True)
), y > 0),
(3, True)
)
l = lambdarepr(p)
eval(h + l)
assert l == "((((1) if (x > 0) else (2))) if (y > 0) else (3))"
def test_sum__1():
# In each case, test eval() the lambdarepr() to make sure that
# it evaluates to the same results as the symbolic expression
s = Sum(x ** i, (i, a, b))
l = lambdarepr(s)
assert l == "(builtins.sum(x**i for i in range(a, b+1)))"
args = x, a, b
f = lambdify(args, s)
v = 2, 3, 8
assert f(*v) == s.subs(zip(args, v)).doit()
def test_sum__2():
s = Sum(i * x, (i, a, b))
l = lambdarepr(s)
assert l == "(builtins.sum(i*x for i in range(a, b+1)))"
args = x, a, b
f = lambdify(args, s)
v = 2, 3, 8
assert f(*v) == s.subs(zip(args, v)).doit()
def test_multiple_sums():
s = Sum(i * x + j, (i, a, b), (j, c, d))
l = lambdarepr(s)
assert l == "(builtins.sum(i*x + j for i in range(a, b+1) for j in range(c, d+1)))"
args = x, a, b, c, d
f = lambdify(args, s)
vals = 2, 3, 4, 5, 6
f_ref = s.subs(zip(args, vals)).doit()
f_res = f(*vals)
assert f_res == f_ref
def test_sqrt():
prntr = LambdaPrinter({'standard' : 'python2'})
assert prntr._print_Pow(sqrt(x), rational=False) == 'sqrt(x)'
assert prntr._print_Pow(sqrt(x), rational=True) == 'x**(1./2.)'
prntr = LambdaPrinter({'standard' : 'python3'})
assert prntr._print_Pow(sqrt(x), rational=True) == 'x**(1/2)'
def test_settings():
raises(TypeError, lambda: lambdarepr(sin(x), method="garbage"))
def test_numexpr():
# test ITE rewrite as Piecewise
from sympy.logic.boolalg import ITE
expr = ITE(x > 0, True, False, evaluate=False)
assert NumExprPrinter().doprint(expr) == \
"evaluate('where((x > 0), True, False)', truediv=True)"
class CustomPrintedObject(Expr):
def _lambdacode(self, printer):
return 'lambda'
def _tensorflowcode(self, printer):
return 'tensorflow'
def _numpycode(self, printer):
return 'numpy'
def _numexprcode(self, printer):
return 'numexpr'
def _mpmathcode(self, printer):
return 'mpmath'
def test_printmethod():
# In each case, printmethod is called to test
# its working
obj = CustomPrintedObject()
assert LambdaPrinter().doprint(obj) == 'lambda'
assert TensorflowPrinter().doprint(obj) == 'tensorflow'
assert NumExprPrinter().doprint(obj) == "evaluate('numexpr', truediv=True)"
assert NumExprPrinter().doprint(Piecewise((y, x >= 0), (z, x < 0))) == \
"evaluate('where((x >= 0), y, z)', truediv=True)"
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