def compare_pretty(a, b):
"""
Is a > b in the sense of ordering in printing?
::
yes ..... return 1
no ...... return -1
equal ... return 0
Strategy:
It uses Basic.compare as a fallback, but improves it in many cases,
like ``x**3``, ``x**4``, ``O(x**3)`` etc. In those simple cases, it just parses the
expression and returns the "sane" ordering such as::
1 < x < x**2 < x**3 < O(x**4) etc.
Examples
========
>>> from sympy.abc import x
>>> from sympy import Basic, Number
>>> Basic._compare_pretty(x, x**2)
-1
>>> Basic._compare_pretty(x**2, x**2)
0
>>> Basic._compare_pretty(x**3, x**2)
1
>>> Basic._compare_pretty(Number(1, 2), Number(1, 3))
1
>>> Basic._compare_pretty(Number(0), Number(-1))
1
"""
try:
a = _sympify(a)
except SympifyError:
pass
try:
b = _sympify(b)
except SympifyError:
pass
# both objects are non-SymPy
if (not isinstance(a, Basic)) and (not isinstance(b, Basic)):
return cmp(a, b)
if not isinstance(a, Basic):
return -1 # other < sympy
if not isinstance(b, Basic):
return +1 # sympy > other
# now both objects are from SymPy, so we can proceed to usual comparison
return cmp(a.sort_key(), b.sort_key())
def compare_pretty(a, b):
"""
Is a > b in the sense of ordering in printing?
::
yes ..... return 1
no ...... return -1
equal ... return 0
Strategy:
It uses Basic.compare as a fallback, but improves it in many cases,
like x**3, x**4, O(x**3) etc. In those simple cases, it just parses the
expression and returns the "sane" ordering such as::
1 < x < x**2 < x**3 < O(x**4) etc.
Examples
========
>>> from sympy.abc import x
>>> from sympy import Basic, Number
>>> Basic._compare_pretty(x, x**2)
-1
>>> Basic._compare_pretty(x**2, x**2)
0
>>> Basic._compare_pretty(x**3, x**2)
1
>>> Basic._compare_pretty(Number(1, 2), Number(1, 3))
1
>>> Basic._compare_pretty(Number(0), Number(-1))
1
"""
try:
a = _sympify(a)
except SympifyError:
pass
try:
b = _sympify(b)
except SympifyError:
pass
# both objects are non-SymPy
if (not isinstance(a, Basic)) and (not isinstance(b, Basic)):
return cmp(a,b)
if not isinstance(a, Basic):
return -1 # other < sympy
if not isinstance(b, Basic):
return +1 # sympy > other
# now both objects are from SymPy, so we can proceed to usual comparison
return cmp(a.sort_key(), b.sort_key())
def compare(self, other):
"""
Return -1, 0, 1 if the object is smaller, equal, or greater than other.
Not in the mathematical sense. If the object is of a different type
from the "other" then their classes are ordered according to
the sorted_classes list.
Examples
========
>>> from sympy.abc import x, y
>>> x.compare(y)
-1
>>> x.compare(x)
0
>>> y.compare(x)
1
"""
# all redefinitions of __cmp__ method should start with the
# following three lines:
if self is other:
return 0
c = cmp(self.__class__, other.__class__)
if c:
return c
#
st = self._hashable_content()
ot = other._hashable_content()
c = cmp(len(st), len(ot))
if c:
return c
for l, r in zip(st, ot):
if isinstance(l, Basic):
c = l.compare(r)
elif isinstance(l, frozenset):
c = 0
else:
c = cmp(l, r)
if c:
return c
return 0
def compare(self, other):
"""
Return -1, 0, 1 if the object is smaller, equal, or greater than other.
Not in the mathematical sense. If the object is of a different type
from the "other" then their classes are ordered according to
the sorted_classes list.
Examples
========
>>> from sympy.abc import x, y
>>> x.compare(y)
-1
>>> x.compare(x)
0
>>> y.compare(x)
1
"""
# all redefinitions of __cmp__ method should start with the
# following three lines:
if self is other:
return 0
c = cmp(self.__class__, other.__class__)
if c:
return c
#
st = self._hashable_content()
ot = other._hashable_content()
c = cmp(len(st), len(ot))
if c:
return c
for l, r in zip(st, ot):
if isinstance(l, Basic):
c = l.compare(r)
elif isinstance(l, frozenset):
c = 0
else:
c = cmp(l, r)
if c:
return c
return 0
def _compare_pretty(a, b):
from sympy.series.order import Order
if isinstance(a, Order) and not isinstance(b, Order):
return 1
if not isinstance(a, Order) and isinstance(b, Order):
return -1
if a.is_Rational and b.is_Rational:
return cmp(a.p*b.q, b.p*a.q)
else:
from sympy.core.symbol import Wild
p1, p2, p3 = Wild("p1"), Wild("p2"), Wild("p3")
r_a = a.match(p1 * p2**p3)
if r_a and p3 in r_a:
a3 = r_a[p3]
r_b = b.match(p1 * p2**p3)
if r_b and p3 in r_b:
b3 = r_b[p3]
c = Basic.compare(a3, b3)
if c != 0:
return c
return Basic.compare(a,b)
def _compare_pretty(a, b):
from sympy.series.order import Order
if isinstance(a, Order) and not isinstance(b, Order):
return 1
if not isinstance(a, Order) and isinstance(b, Order):
return -1
if a.is_Rational and b.is_Rational:
return cmp(a.p * b.q, b.p * a.q)
else:
from sympy.core.symbol import Wild
p1, p2, p3 = Wild("p1"), Wild("p2"), Wild("p3")
r_a = a.match(p1 * p2**p3)
if r_a and p3 in r_a:
a3 = r_a[p3]
r_b = b.match(p1 * p2**p3)
if r_b and p3 in r_b:
b3 = r_b[p3]
c = Basic.compare(a3, b3)
if c != 0:
return c
return Basic.compare(a, b)
def _compare_pretty(a, b):
return cmp(str(a), str(b))
def _compare_pretty(a, b):
return cmp(str(a), str(b))