Source code for sympy.printing.str

A Printer for generating readable representation of most sympy classes.

from sympy.core import S, Rational, Pow, Basic, Mul
from sympy.core.function import _coeff_isneg
from printer import Printer
from sympy.printing.precedence import precedence, PRECEDENCE

import sympy.mpmath.libmp as mlib
from sympy.mpmath.libmp import prec_to_dps

from sympy.polys.polyerrors import PolynomialError

from sympy.utilities import default_sort_key

[docs]class StrPrinter(Printer): printmethod = "_sympystr" _default_settings = { "order": None, "full_prec": "auto", } def parenthesize(self, item, level): if precedence(item) <= level: return "(%s)"%self._print(item) else: return self._print(item) def stringify(self, args, sep, level=0): return sep.join([self.parenthesize(item, level) for item in args]) def emptyPrinter(self, expr): if isinstance(expr, str): return expr elif isinstance(expr, Basic): if hasattr(expr, "args"): return repr(expr) else: raise else: return str(expr) def _print_Add(self, expr, order=None): if self.order == 'none': terms = list(expr.args) else: terms = self._as_ordered_terms(expr, order=order) PREC = precedence(expr) l = [] for term in terms: t = self._print(term) if t.startswith('-'): sign = "-" t = t[1:] else: sign = "+" if precedence(term) < PREC: l.extend([sign, "(%s)"%t]) else: l.extend([sign, t]) sign = l.pop(0) if sign=='+': sign = "" return sign + ' '.join(l) def _print_And(self, expr): return '%s(%s)' % (expr.func, ', '.join(sorted(self._print(a) for a in expr.args))) def _print_Or(self, expr): return '%s(%s)' % (expr.func, ', '.join(sorted(self._print(a) for a in expr.args))) def _print_AppliedPredicate(self, expr): return '%s(%s)' % (expr.func, expr.arg) def _print_Basic(self, expr): l = [self._print(o) for o in expr.args] return expr.__class__.__name__ + "(%s)"%", ".join(l) def _print_BlockMatrix(self, B): if B.mat.shape == (1, 1): self._print(B.mat[0,0]) return self._print(B.mat) def _print_Catalan(self, expr): return 'Catalan' def _print_ComplexInfinity(self, expr): return 'zoo' def _print_Derivative(self, expr): return 'Derivative(%s)'%", ".join(map(self._print, expr.args)) def _print_dict(self, d): keys = sorted(d.keys(), key=default_sort_key) items = [] for key in keys: item = "%s: %s" % (self._print(key), self._print(d[key])) items.append(item) return "{%s}"%", ".join(items) def _print_Dict(self, expr): return self._print_dict(expr) def _print_RandomDomain(self, d): try: return 'Domain: '+self._print(d.as_boolean()) except: try: return ('Domain: ' + self._print(d.symbols) + ' in ' + self._print(d.set)) except: return 'Domain on ' + self._print(d.symbols) def _print_Dummy(self, expr): return '_' + def _print_EulerGamma(self, expr): return 'EulerGamma' def _print_Exp1(self, expr): return 'E' def _print_ExprCondPair(self, expr): return '(%s, %s)' % (expr.expr, expr.cond) def _print_factorial(self, expr): return "%s!" % self.parenthesize(expr.args[0], PRECEDENCE["Pow"]) def _print_FiniteSet(self, s): s = sorted(s, key=default_sort_key) if len(s) > 10: printset = s[:3] + ['...'] + s[-3:] else: printset = s return '{' + ', '.join(self._print(el) for el in printset) + '}' def _print_Function(self, expr): return expr.func.__name__ + "(%s)"%self.stringify(expr.args, ", ") def _print_GeometryEntity(self, expr): # GeometryEntity is special -- it's base is tuple return str(expr) def _print_GoldenRatio(self, expr): return 'GoldenRatio' def _print_ImaginaryUnit(self, expr): return 'I' def _print_Infinity(self, expr): return 'oo' def _print_Integral(self, expr): def _xab_tostr(xab): if len(xab) == 1: return self._print(xab[0]) else: return self._print((xab[0],) + tuple(xab[1:])) L = ', '.join([_xab_tostr(l) for l in expr.limits]) return 'Integral(%s, %s)' % (self._print(expr.function), L) def _print_Interval(self, i): if i.left_open: left = '(' else: left = '[' if i.right_open: right = ')' else: right = ']' return "%s%s, %s%s" % \ (left, self._print(i.start), self._print(i.end), right) def _print_Inverse(self, I): return "%s^-1" % self.parenthesize(I.arg, PRECEDENCE["Pow"]) def _print_Lambda(self, obj): args, expr = obj.args if len(args) == 1: return "Lambda(%s, %s)" % (args.args[0], expr) else: arg_string = ", ".join(self._print(arg) for arg in args) return "Lambda((%s), %s" % (arg_string, expr) def _print_LatticeOp(self, expr): args = sorted(expr.args, key=default_sort_key) return expr.func.__name__ + "(%s)"%", ".join(self._print(arg) for arg in args) def _print_Limit(self, expr): e, z, z0, dir = expr.args if str(dir) == "+": return "Limit(%s, %s, %s)" % (e, z, z0) else: return "Limit(%s, %s, %s, dir='%s')" % (e, z, z0, dir) def _print_list(self, expr): return "[%s]"%self.stringify(expr, ", ") def _print_MatrixBase(self, expr): return expr._format_str(lambda elem: self._print(elem)) _print_ImmutableMatrix = _print_MatrixBase _print_MutableMatrix = _print_MatrixBase def _print_DeferredVector(self, expr): return def _print_Mul(self, expr): prec = precedence(expr) if _coeff_isneg(expr): expr = -expr sign = "-" else: sign = "" a = [] # items in the numerator b = [] # items that are in the denominator (if any) if self.order not in ('old', 'none'): args = expr.as_ordered_factors() else: # use make_args in case expr was something like -x -> x args = Mul.make_args(expr) # Gather args for numerator/denominator for item in args: if item.is_commutative and item.is_Pow and item.exp.is_Rational and item.exp.is_negative: if item.exp != -1: b.append(Pow(item.base, -item.exp, evaluate=False)) else: b.append(Pow(item.base, -item.exp)) elif item.is_Rational and item is not S.Infinity: if item.p != 1: a.append(Rational(item.p)) if item.q != 1: b.append(Rational(item.q)) else: a.append(item) a = a or [S.One] a_str = map(lambda x:self.parenthesize(x, prec), a) b_str = map(lambda x:self.parenthesize(x, prec), b) if len(b) == 0: return sign + '*'.join(a_str) elif len(b) == 1: if len(a) == 1 and not (a[0].is_Atom or a[0].is_Add): return sign + "%s/"%a_str[0] + '*'.join(b_str) else: return sign + '*'.join(a_str) + "/%s"%b_str[0] else: return sign + '*'.join(a_str) + "/(%s)"%'*'.join(b_str) def _print_MatMul(self, expr): return '*'.join([self.parenthesize(arg, precedence(expr)) for arg in expr.args]) def _print_NaN(self, expr): return 'nan' def _print_NegativeInfinity(self, expr): return '-oo' def _print_Normal(self, expr): return "Normal(%s, %s)"%(, expr.sigma) def _print_Order(self, expr): if len(expr.variables) <= 1: return 'O(%s)'%self._print(expr.expr) else: return 'O(%s)'%self.stringify(expr.args, ', ', 0) def _print_Cycle(self, expr): """We want it to print as Cycle in doctests for which a repr is required. With __repr__ defined in Cycle, interactive output gives Cycle form but during doctests, the dict's __repr__ form is used. Defining this _print function solves that problem. >>> from sympy.combinatorics import Cycle >>> Cycle(1, 2) # will print as a dict without this method Cycle(1, 2) """ return expr.__repr__() def _print_Permutation(self, expr): from sympy.combinatorics.permutations import Permutation, Cycle if Permutation.print_cyclic: if not expr.size: return 'Permutation()' # before taking Cycle notation, see if the last element is # a singleton and move it to the head of the string s = Cycle(expr)(expr.size - 1).__repr__()[len('Cycle'):] last = s.rfind('(') if not last == 0 and ',' not in s[last:]: s = s[last:] + s[:last] return 'Permutation%s' % s else: s = if not s: if expr.size < 5: return 'Permutation(%s)' % str(expr.array_form) return 'Permutation([], size=%s)' % expr.size trim = str(expr.array_form[:s[-1] + 1]) + ', size=%s' % expr.size use = full = str(expr.array_form) if len(trim) < len(full): use = trim return 'Permutation(%s)' % use def _print_PermutationGroup(self, expr): p = [' %s' % str(a) for a in expr.args] return 'PermutationGroup([\n%s])' % ',\n'.join(p) def _print_PDF(self, expr): return 'PDF(%s, (%s, %s, %s))' % \ (self._print(expr.pdf.args[1]), self._print(expr.pdf.args[0]), \ self._print(expr.domain[0]), self._print(expr.domain[1])) def _print_Pi(self, expr): return 'pi' def _print_Poly(self, expr): terms, gens = [], [ self._print(s) for s in expr.gens ] for monom, coeff in expr.terms(): s_monom = [] for i, exp in enumerate(monom): if exp > 0: if exp == 1: s_monom.append(gens[i]) else: s_monom.append(gens[i] + "**%d" % exp) s_monom = "*".join(s_monom) if coeff.is_Add: if s_monom: s_coeff = "(" + self._print(coeff) + ")" else: s_coeff = self._print(coeff) else: if s_monom: if coeff is S.One: terms.extend(['+', s_monom]) continue if coeff is S.NegativeOne: terms.extend(['-', s_monom]) continue s_coeff = self._print(coeff) if not s_monom: s_term = s_coeff else: s_term = s_coeff + "*" + s_monom if s_term.startswith('-'): terms.extend(['-', s_term[1:]]) else: terms.extend(['+', s_term]) if terms[0] in ['-', '+']: modifier = terms.pop(0) if modifier == '-': terms[0] = '-' + terms[0] format = expr.__class__.__name__ + "(%s, %s" try: format += ", modulus=%s" % expr.get_modulus() except PolynomialError: format += ", domain='%s'" % expr.get_domain() format += ")" return format % (' '.join(terms), ', '.join(gens)) def _print_ProductSet(self, p): return ' x '.join(self._print(set) for set in p.sets) def _print_AlgebraicNumber(self, expr): if expr.is_aliased: return self._print(expr.as_poly().as_expr()) else: return self._print(expr.as_expr()) def _print_Pow(self, expr, rational=False): PREC = precedence(expr) if expr.exp is S.Half and not rational: return "sqrt(%s)" % self._print(expr.base) if expr.is_commutative: if -expr.exp is S.Half and not rational: # Note: Don't test "expr.exp == -S.Half" here, because that will # match -0.5, which we don't want. return "1/sqrt(%s)" % self._print(expr.base) if expr.exp == -1: return '1/%s' % self.parenthesize(expr.base, PREC) e = self.parenthesize(expr.exp, PREC) if self.printmethod == '_sympyrepr' and expr.exp.is_Rational and expr.exp.q != 1: # the parenthesized exp should be '(Rational(a, b))' so strip parens, # but just check to be sure. if e.startswith('(Rational'): return '%s**%s' % (self.parenthesize(expr.base, PREC), e[1:-1]) return '%s**%s' % (self.parenthesize(expr.base, PREC), e) def _print_MatPow(self, expr): PREC = precedence(expr) return '%s**%s'%(self.parenthesize(expr.base, PREC), self.parenthesize(expr.exp, PREC)) def _print_Integer(self, expr): return str(expr.p) def _print_int(self, expr): return str(expr) def _print_mpz(self, expr): return str(expr) def _print_Rational(self, expr): return '%s/%s' % (expr.p, expr.q) def _print_Fraction(self, expr): return '%s/%s' % (expr.numerator, expr.denominator) def _print_mpq(self, expr): return '%s/%s' % (expr.numer(), expr.denom()) def _print_Float(self, expr): prec = expr._prec if prec < 5: dps = 0 else: dps = prec_to_dps(expr._prec) if self._settings["full_prec"] == True: strip = False elif self._settings["full_prec"] == False: strip = True elif self._settings["full_prec"] == "auto": strip = self._print_level > 1 rv = mlib.to_str(expr._mpf_, dps, strip_zeros=strip) if rv.startswith('-.0'): rv = '-0.' + rv[3:] elif rv.startswith('.0'): rv = '0.' + rv[2:] return rv def _print_Relational(self, expr): return '%s %s %s'%(self.parenthesize(expr.lhs, precedence(expr)), expr.rel_op, self.parenthesize(expr.rhs, precedence(expr))) def _print_RootOf(self, expr): return "RootOf(%s, %d)" % (self._print_Add(expr.expr, order='lex'), expr.index) def _print_RootSum(self, expr): args = [self._print_Add(expr.expr, order='lex')] if is not S.IdentityFunction: args.append(self._print( return "RootSum(%s)" % ", ".join(args) def _print_GroebnerBasis(self, basis): cls = basis.__class__.__name__ exprs = [ self._print_Add(arg, order=basis.order) for arg in basis.exprs ] exprs = "[%s]" % ", ".join(exprs) gens = [ self._print(gen) for gen in basis.gens ] domain = "domain='%s'" % self._print(basis.domain) order = "order='%s'" % self._print(basis.order) args = [exprs] + gens + [domain, order] return "%s(%s)" % (cls, ", ".join(args)) def _print_Sample(self, expr): return "Sample([%s])"%self.stringify(expr, ", ", 0) def _print_set(self, s): items = sorted(s, key=default_sort_key) args = ', '.join(self._print(item) for item in items) if args: args = '[%s]' % args return '%s(%s)' % (type(s).__name__, args) _print_frozenset = _print_set def _print_SparseMatrix(self, expr): return self._print(expr.toMatrix()) def _print_Sum(self, expr): def _xab_tostr(xab): if len(xab) == 1: return self._print(xab[0]) else: return self._print((xab[0],) + tuple(xab[1:])) L = ', '.join([_xab_tostr(l) for l in expr.limits]) return 'Sum(%s, %s)' % (self._print(expr.function), L) def _print_Symbol(self, expr): return def _print_Predicate(self, expr): return "Q.%s" % def _print_str(self, expr): return expr def _print_tuple(self, expr): if len(expr)==1: return "(%s,)"%self._print(expr[0]) else: return "(%s)"%self.stringify(expr, ", ") def _print_Tuple(self, expr): return self._print_tuple(expr) def _print_Transpose(self, T): return "%s'" % self.parenthesize(T.arg, PRECEDENCE["Pow"]) def _print_Uniform(self, expr): return "Uniform(%s, %s)"%(expr.a, expr.b) def _print_Union(self, expr): return ' U '.join(self._print(set) for set in expr.args) def _print_Unit(self, expr): return expr.abbrev def _print_Wild(self, expr): return + '_' def _print_WildFunction(self, expr): return + '_' def _print_Zero(self, expr): return "0" def _print_DMP(self, p): from sympy.core.sympify import SympifyError try: if p.ring is not None: # TODO incorporate order return self._print(p.ring.to_sympy(p)) except SympifyError: pass cls = p.__class__.__name__ rep = self._print(p.rep) dom = self._print(p.dom) ring = self._print(p.ring) return "%s(%s, %s, %s)" % (cls, rep, dom, ring) def _print_DMF(self, expr): return self._print_DMP(expr) def _print_Object(self, object): return 'Object("%s")' % def _print_IdentityMorphism(self, morphism): return 'IdentityMorphism(%s)' % morphism.domain def _print_NamedMorphism(self, morphism): return 'NamedMorphism(%s, %s, "%s")' % \ (morphism.domain, morphism.codomain, def _print_Category(self, category): return 'Category("%s")' % def _print_BaseScalarField(self, field): return field._coord_sys._names[field._index] def _print_BaseVectorField(self, field): return 'e_%s'%field._coord_sys._names[field._index] def _print_Differential(self, diff): field = diff._form_field if hasattr(field, '_coord_sys'): return 'd%s'%field._coord_sys._names[field._index] else: return 'd(%s)'%self._print(field) def _print_Tr(self, expr): #TODO : Handle indices return "%s(%s)" % ("Tr", self._print(expr.args[0]))
def sstr(expr, **settings): """Returns the expression as a string. For large expressions where speed is a concern, use the setting order='none'. Examples ======== >>> from sympy import symbols, Eq, sstr >>> a, b = symbols('a b') >>> sstr(Eq(a + b, 0)) 'a + b == 0' """ p = StrPrinter(settings) s = p.doprint(expr) return s class StrReprPrinter(StrPrinter): """(internal) -- see sstrrepr""" def _print_str(self, s): return repr(s)
[docs]def sstrrepr(expr, **settings): """return expr in mixed str/repr form i.e. strings are returned in repr form with quotes, and everything else is returned in str form. This function could be useful for hooking into sys.displayhook """ p = StrReprPrinter(settings) s = p.doprint(expr) return s