Update of /cvsroot/python/python/nondist/sandbox/decimal In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv26046 Modified Files: Decimal.py Log Message: * Part III: docstrings and doctests * Localize some inner loop variables Index: Decimal.py =================================================================== RCS file: /cvsroot/python/python/nondist/sandbox/decimal/Decimal.py,v retrieving revision 1.32 retrieving revision 1.33 diff -C2 -d -r1.32 -r1.33 *** Decimal.py 30 Jun 2004 08:16:42 -0000 1.32 --- Decimal.py 30 Jun 2004 18:49:07 -0000 1.33 *************** *** 1038,1041 **** --- 1038,1042 ---- op1, op2 = op2, op1 + _divmod = divmod accumulator = [0]*(len(self._int) + len(other._int)) for i in xrange(len(op2)): *************** *** 1045,1049 **** carry = 0 for j in xrange(len(op1)): ! carry, accumulator[i+j] = divmod( mult * op1[j] + carry + accumulator[i+j], 10) --- 1046,1050 ---- carry = 0 for j in xrange(len(op1)): ! carry, accumulator[i+j] = _divmod( mult * op1[j] + carry + accumulator[i+j], 10) *************** *** 2204,2214 **** --- 2205,2267 ---- #Methods def abs(self, a): + """Returns the absolute value of the operand. + + If the operand is negative, the result is the same as using the minus + operation on the operand. Otherwise, the result is the same as using + the plus operation on the operand. + + >>> Context(prec=9).abs(Decimal('2.1')) + Decimal("2.1") + >>> Context(prec=9).abs(Decimal('-100')) + Decimal("100") + >>> Context(prec=9).abs(Decimal('101.5')) + Decimal("101.5") + >>> Context(prec=9).abs(Decimal('-101.5')) + Decimal("101.5") + """ return a.__abs__(context=self) + def add(self, a, b): + """Return the sum of the two operands. + + >>> Context(prec=9).add(Decimal('12'), Decimal('7.00')) + Decimal("19.00") + >>> Context(prec=9).add(Decimal('1E+2'), Decimal('1.01E+4')) + Decimal("1.02E+4") + """ return a.__add__(b, context=self) + def _apply(self, a): return str(a._fix(context=self)) + def compare(self, a, b): + """Compares values numerically. + + If the signs of the operands differ, a value representing each operand + (’-1’ if the operand is less than zero, ’0’ if the operand is zero or + negative zero, or ’1’ if the operand is greater than zero) is used in + place of that operand for the comparison instead of the actual + operand. + + The comparison is then effected by subtracting the second operand from + the first and then returning a value according to the result of the + subtraction: ’-1’ if the result is less than zero, ’0’ if the result is + zero or negative zero, or ’1’ if the result is greater than zero. + + >>> Context(prec=9).compare(Decimal('2.1'), Decimal('3')) + Decimal("-1") + >>> Context(prec=9).compare(Decimal('2.1'), Decimal('2.1')) + Decimal("0") + >>> Context(prec=9).compare(Decimal('2.1'), Decimal('2.10')) + Decimal("0") + >>> Context(prec=9).compare(Decimal('3'), Decimal('2.1')) + Decimal("1") + >>> Context(prec=9).compare(Decimal('2.1'), Decimal('-3')) + Decimal("1") + >>> Context(prec=9).compare(Decimal('-3'), Decimal('2.1')) + Decimal("-1") + """ return a.compare(b, context=self) + def divide(self, a, b): """Decimal division in a specified context. *************** *** 2251,2254 **** --- 2304,2308 ---- def divmod(self, a, b): return a.__divmod__(b, context=self) + def max(self, a,b): """max compares two values numerically and returns the maximum. *************** *** 2466,2483 **** --- 2520,2617 ---- def same_quantum(self, a, b): + """Returns True if the two operands have the same exponent. + + The result is never affected by either the sign or the coefficient of + either operand. + + >>> Context(prec=9).same_quantum(Decimal('2.17'), Decimal('0.001')) + False + >>> Context(prec=9).same_quantum(Decimal('2.17'), Decimal('0.01')) + True + >>> Context(prec=9).same_quantum(Decimal('2.17'), Decimal('1')) + False + >>> Context(prec=9).same_quantum(Decimal('Inf'), Decimal('-Inf')) + True + """ return a.same_quantum(b) + def sqrt(self, a): + """Returns the square root of a non-negative number to context precision. + + If the result must be inexact, it is rounded using the round-half-even + algorithm. + + >>> Context(prec=9).sqrt(Decimal('0')) + Decimal("0") + >>> Context(prec=9).sqrt(Decimal('-0')) + Decimal("-0") + >>> Context(prec=9).sqrt(Decimal('0.39')) + Decimal("0.624499800") + >>> Context(prec=9).sqrt(Decimal('100')) + Decimal("10") + >>> Context(prec=9).sqrt(Decimal('1')) + Decimal("1") + >>> Context(prec=9).sqrt(Decimal('1.0')) + Decimal("1.0") + >>> Context(prec=9).sqrt(Decimal('1.00')) + Decimal("1.0") + >>> Context(prec=9).sqrt(Decimal('7')) + Decimal("2.64575131") + >>> Context(prec=9).sqrt(Decimal('10')) + Decimal("3.16227766") + """ return a.sqrt(context=self) + def subtract(self, a, b): + """Return the sum of the two operands. + + >>> Context(prec=9).subtract(Decimal('1.3'), Decimal('1.07')) + Decimal("0.23") + >>> Context(prec=9).subtract(Decimal('1.3'), Decimal('1.30')) + Decimal("0.00") + >>> Context(prec=9).subtract(Decimal('1.3'), Decimal('2.07')) + Decimal("-0.77") + """ return a.__sub__(b, context=self) + def to_eng_string(self, a): return a.to_eng_string(context=self) + def to_sci_string(self, a): return a.__str__(context=self) + def to_integral(self, a): + """Rounds to an integer. + + When the operand has a negative exponent, the result is the same + as using the quantize() operation using the given operand as the + left-hand-operand, 1E+0 as the right-hand-operand, and the precision + of the operand as the precision setting, except that no flags will + be set. The rounding mode is taken from the context. + + >>> Context(prec=9).to_integral(Decimal('2.1')) + Decimal("2") + >>> Context(prec=9).to_integral(Decimal('100')) + Decimal("100") + >>> Context(prec=9).to_integral(Decimal('100.0')) + Decimal("100") + >>> Context(prec=9).to_integral(Decimal('101.5')) + Decimal("102") + >>> Context(prec=9).to_integral(Decimal('-101.5')) + Decimal("-102") + >>> Context(prec=9).to_integral(Decimal('10E+5')) + Decimal("1.0E+6") + >>> Context(prec=9).to_integral(Decimal('7.89E+77')) + Decimal("7.89E+77") + >>> Context(prec=9).to_integral(Decimal('-Inf')) + Decimal("-Infinity") + """ return a.to_integral(context=self) class _WorkRep(object): __slots__ = ('sign','int','exp') + # sign: -1 None 1 + # int: list + # exp: None, int, or string def __init__(self, value=None): *************** *** 2559,2582 **** """ ! self.int.reverse() alist.reverse() carry = 0 for x in xrange(len(alist)): ! self.int[x] -= alist[x] + carry ! if self.int[x] < 0: carry = 1 ! self.int[x] += 10 else: carry = 0 if carry: ! self.int[x+1] -= 1 ! last = len(self.int)-1 ! while len(self.int) > 1 and self.int[last] == 0: last -= 1 if last == 0: break ! self.int[last+1:]=[] ! self.int.reverse() alist.reverse() return --- 2693,2717 ---- """ ! selfint = self.int ! selfint.reverse() alist.reverse() carry = 0 for x in xrange(len(alist)): ! selfint[x] -= alist[x] + carry ! if selfint[x] < 0: carry = 1 ! selfint[x] += 10 else: carry = 0 if carry: ! selfint[x+1] -= 1 ! last = len(selfint)-1 ! while len(selfint) > 1 and selfint[last] == 0: last -= 1 if last == 0: break ! selfint[last+1:]=[] ! selfint.reverse() alist.reverse() return