Improve Context construction and representation:
* Rename "trap_enablers" to just "traps".
* Simplify names of "settraps" and "setflags" to just "traps" and "flags".
* Show "capitals" in the context representation
* Simplify the Context constructor to match its repr form so that only
the set flags and traps need to be listed.
* Representation can now be run through eval().
Improve the error message when the Decimal constructor is given a float.
The test suite no longer needs a duplicate reset_flags method.
diff --git a/Lib/decimal.py b/Lib/decimal.py
index d9c3f10..85e0f34 100644
--- a/Lib/decimal.py
+++ b/Lib/decimal.py
@@ -70,7 +70,7 @@
-Infinity
>>> print dig / 0
Infinity
->>> getcontext().trap_enablers[DivisionByZero] = 1
+>>> getcontext().traps[DivisionByZero] = 1
>>> print dig / 0
Traceback (most recent call last):
...
@@ -78,12 +78,12 @@
...
DivisionByZero: x / 0
>>> c = Context()
->>> c.trap_enablers[InvalidOperation] = 0
+>>> c.traps[InvalidOperation] = 0
>>> print c.flags[InvalidOperation]
0
>>> c.divide(Decimal(0), Decimal(0))
Decimal("NaN")
->>> c.trap_enablers[InvalidOperation] = 1
+>>> c.traps[InvalidOperation] = 1
>>> print c.flags[InvalidOperation]
1
>>> c.flags[InvalidOperation] = 0
@@ -98,7 +98,7 @@
>>> print c.flags[InvalidOperation]
1
>>> c.flags[InvalidOperation] = 0
->>> c.trap_enablers[InvalidOperation] = 0
+>>> c.traps[InvalidOperation] = 0
>>> print c.divide(Decimal(0), Decimal(0))
NaN
>>> print c.flags[InvalidOperation]
@@ -495,7 +495,11 @@
self._int = value._int
return
- raise TypeError("Can't convert %r" % value)
+ if isinstance(value, float):
+ raise TypeError("Cannot convert float to Decimal. " +
+ "First convert the float to a string")
+
+ raise TypeError("Cannot convert %r" % value)
def _convert_other(self, other):
"""Convert other to Decimal.
@@ -2096,7 +2100,7 @@
prec - precision (for use in rounding, division, square roots..)
rounding - rounding type. (how you round)
_rounding_decision - ALWAYS_ROUND, NEVER_ROUND -- do you round?
- trap_enablers - If trap_enablers[exception] = 1, then the exception is
+ traps - If traps[exception] = 1, then the exception is
raised when it is caused. Otherwise, a value is
substituted in.
flags - When an exception is caused, flags[exception] is incremented.
@@ -2110,13 +2114,15 @@
"""
def __init__(self, prec=None, rounding=None,
- trap_enablers=None, flags=None,
+ traps=None, flags=[],
_rounding_decision=None,
Emin=None, Emax=None,
capitals=None, _clamp=0,
_ignored_flags=[]):
- if flags is None:
- flags = dict.fromkeys(Signals, 0)
+ if not isinstance(flags, dict):
+ flags = dict([(s,s in flags) for s in Signals])
+ if traps is not None and not isinstance(traps, dict):
+ traps = dict([(s,s in traps) for s in Signals])
for name, val in locals().items():
if val is None:
setattr(self, name, copy.copy(getattr(DefaultContext, name)))
@@ -2125,11 +2131,11 @@
del self.self
def __repr__(self):
- """Show the current context in readable form, not in a form for eval()."""
+ """Show the current context."""
s = []
- s.append('Context(prec=%(prec)d, rounding=%(rounding)s, Emin=%(Emin)d, Emax=%(Emax)d' % vars(self))
- s.append('setflags=%r' % [f.__name__ for f, v in self.flags.items() if v])
- s.append('settraps=%r' % [t.__name__ for t, v in self.trap_enablers.items() if v])
+ s.append('Context(prec=%(prec)d, rounding=%(rounding)s, Emin=%(Emin)d, Emax=%(Emax)d, capitals=%(capitals)d' % vars(self))
+ s.append('flags=[' + ', '.join([f.__name__ for f, v in self.flags.items() if v]) + ']')
+ s.append('traps=[' + ', '.join([t.__name__ for t, v in self.traps.items() if v]) + ']')
return ', '.join(s) + ')'
def clear_flags(self):
@@ -2139,7 +2145,7 @@
def copy(self):
"""Returns a copy from self."""
- nc = Context(self.prec, self.rounding, self.trap_enablers, self.flags,
+ nc = Context(self.prec, self.rounding, self.traps, self.flags,
self._rounding_decision, self.Emin, self.Emax,
self.capitals, self._clamp, self._ignored_flags)
return nc
@@ -2159,7 +2165,7 @@
return error().handle(self, *args)
self.flags[error] += 1
- if not self.trap_enablers[error]:
+ if not self.traps[error]:
#The errors define how to handle themselves.
return condition().handle(self, *args)
@@ -2946,13 +2952,10 @@
# The default context prototype used by Context()
# Is mutable, so than new contexts can have different default values
-_default_traps = dict.fromkeys(Signals, 0)
-_default_traps.update({DivisionByZero:1, Overflow:1, InvalidOperation:1})
-
DefaultContext = Context(
prec=28, rounding=ROUND_HALF_EVEN,
- trap_enablers=_default_traps,
- flags=None,
+ traps=[DivisionByZero, Overflow, InvalidOperation],
+ flags=[],
_rounding_decision=ALWAYS_ROUND,
Emax=DEFAULT_MAX_EXPONENT,
Emin=DEFAULT_MIN_EXPONENT,
@@ -2964,20 +2967,17 @@
# contexts and be able to reproduce results from other implementations
# of the spec.
-_basic_traps = dict.fromkeys(Signals, 1)
-_basic_traps.update({Inexact:0, Rounded:0, Subnormal:0})
-
BasicContext = Context(
prec=9, rounding=ROUND_HALF_UP,
- trap_enablers=_basic_traps,
- flags=None,
+ traps=[DivisionByZero, Overflow, InvalidOperation, Clamped, Underflow],
+ flags=[],
_rounding_decision=ALWAYS_ROUND,
)
ExtendedContext = Context(
prec=9, rounding=ROUND_HALF_EVEN,
- trap_enablers=dict.fromkeys(Signals, 0),
- flags=None,
+ traps=[],
+ flags=[],
_rounding_decision=ALWAYS_ROUND,
)