Source code for sympy.printing.lambdarepr

from __future__ import print_function, division

from .str import StrPrinter
from sympy.utilities import default_sort_key


[docs]class LambdaPrinter(StrPrinter): """ This printer converts expressions into strings that can be used by lambdify. """ def _print_MatrixBase(self, expr): return "%s(%s)" % (expr.__class__.__name__, str(expr.tolist())) _print_SparseMatrix = \ _print_MutableSparseMatrix = \ _print_ImmutableSparseMatrix = \ _print_Matrix = \ _print_DenseMatrix = \ _print_MutableDenseMatrix = \ _print_ImmutableMatrix = \ _print_ImmutableDenseMatrix = \ _print_MatrixBase def _print_Piecewise(self, expr): from sympy.sets.sets import Interval result = [] i = 0 for arg in expr.args: e = arg.expr c = arg.cond result.append('((') result.append(self._print(e)) result.append(') if (') result.append(self._print(c)) result.append(') else (') i += 1 result = result[:-1] result.append(') else None)') result.append(')'*(2*i - 2)) return ''.join(result) def _print_And(self, expr): result = ['('] for arg in sorted(expr.args, key=default_sort_key): result.extend(['(', self._print(arg), ')']) result.append(' and ') result = result[:-1] result.append(')') return ''.join(result) def _print_Or(self, expr): result = ['('] for arg in sorted(expr.args, key=default_sort_key): result.extend(['(', self._print(arg), ')']) result.append(' or ') result = result[:-1] result.append(')') return ''.join(result) def _print_Not(self, expr): result = ['(', 'not (', self._print(expr.args[0]), '))'] return ''.join(result) def _print_BooleanTrue(self, expr): return "True" def _print_BooleanFalse(self, expr): return "False" # numexpr works by altering the string passed to numexpr.evaluate # rather than by populating a namespace. Thus a special printer...
class NumExprPrinter(LambdaPrinter): # key, value pairs correspond to sympy name and numexpr name # functions not appearing in this dict will raise a TypeError _numexpr_functions = { 'sin' : 'sin', 'cos' : 'cos', 'tan' : 'tan', 'asin': 'arcsin', 'acos': 'arccos', 'atan': 'arctan', 'atan2' : 'arctan2', 'sinh' : 'sinh', 'cosh' : 'cosh', 'tanh' : 'tanh', 'asinh': 'arcsinh', 'acosh': 'arccosh', 'atanh': 'arctanh', 'ln' : 'log', 'log': 'log', 'exp': 'exp', 'sqrt' : 'sqrt', 'Abs' : 'abs', 'conjugate' : 'conj', 'im' : 'imag', 're' : 'real', 'where' : 'where', 'complex' : 'complex', 'contains' : 'contains', } def _print_ImaginaryUnit(self, expr): return '1j' def _print_seq(self, seq, delimiter=', '): # simplified _print_seq taken from pretty.py s = [self._print(item) for item in seq] if s: return delimiter.join(s) else: return "" def _print_Function(self, e): func_name = e.func.__name__ nstr = self._numexpr_functions.get(func_name, None) if nstr is None: # check for implemented_function if hasattr(e, '_imp_'): return "(%s)" % self._print(e._imp_(*e.args)) else: raise TypeError("numexpr does not support function '%s'" % func_name) return "%s(%s)" % (nstr, self._print_seq(e.args)) def blacklisted(self, expr): raise TypeError("numexpr cannot be used with %s" % expr.__class__.__name__) # blacklist all Matrix printing _print_SparseMatrix = \ _print_MutableSparseMatrix = \ _print_ImmutableSparseMatrix = \ _print_Matrix = \ _print_DenseMatrix = \ _print_MutableDenseMatrix = \ _print_ImmutableMatrix = \ _print_ImmutableDenseMatrix = \ blacklisted # blacklist some python expressions _print_list = \ _print_tuple = \ _print_Tuple = \ _print_dict = \ _print_Dict = \ blacklisted def doprint(self, expr): lstr = super(NumExprPrinter, self).doprint(expr) return "evaluate('%s')" % lstr
[docs]def lambdarepr(expr, **settings): """ Returns a string usable for lambdifying. """ return LambdaPrinter(settings).doprint(expr)