File size: 6,947 Bytes
6a86ad5
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
from sympy.concrete.summations import Sum
from sympy.core.expr import Expr
from sympy.core.symbol import symbols
from sympy.functions.elementary.miscellaneous import sqrt
from sympy.functions.elementary.piecewise import Piecewise
from sympy.functions.elementary.trigonometric import sin
from sympy.matrices.dense import MutableDenseMatrix as Matrix
from sympy.sets.sets import Interval
from sympy.utilities.lambdify import lambdify
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():
    # Test printing a Matrix that has an element that is printed differently
    # with the LambdaPrinter than with the StrPrinter.
    e = x % 2
    assert lambdarepr(e) != str(e)
    assert lambdarepr(Matrix([e])) == 'ImmutableDenseMatrix([[x % 2]])'


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, 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' : 'python3'})
    assert prntr._print_Pow(sqrt(x), rational=False) == 'sqrt(x)'
    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) == \
           "numexpr.evaluate('where((x > 0), True, False)', truediv=True)"

    from sympy.codegen.ast import Return, FunctionDefinition, Variable, Assignment
    func_def = FunctionDefinition(None, 'foo', [Variable(x)], [Assignment(y,x), Return(y**2)])
    expected = "def foo(x):\n"\
               "    y = numexpr.evaluate('x', truediv=True)\n"\
               "    return numexpr.evaluate('y**2', truediv=True)"
    assert NumExprPrinter().doprint(func_def) == expected


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) == "numexpr.evaluate('numexpr', truediv=True)"

    assert NumExprPrinter().doprint(Piecewise((y, x >= 0), (z, x < 0))) == \
            "numexpr.evaluate('where((x >= 0), y, z)', truediv=True)"