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/Doc/lib/libdecimal.tex b/Doc/lib/libdecimal.tex
index b6164fc..a00feb3 100644
--- a/Doc/lib/libdecimal.tex
+++ b/Doc/lib/libdecimal.tex
@@ -112,7 +112,7 @@
>>> from decimal import *
>>> getcontext()
Context(prec=28, rounding=ROUND_HALF_EVEN, Emin=-999999999, Emax=999999999,
- setflags=[], settraps=[])
+ capitals=1, flags=[], traps=[])
>>> getcontext().prec = 7
\end{verbatim}
@@ -204,10 +204,10 @@
>>> myothercontext = Context(prec=60, rounding=ROUND_HALF_DOWN)
>>> myothercontext
Context(prec=60, rounding=ROUND_HALF_DOWN, Emin=-999999999, Emax=999999999,
- setflags=[], settraps=[])
+ capitals=1, flags=[], traps=[])
>>> ExtendedContext
Context(prec=9, rounding=ROUND_HALF_EVEN, Emin=-999999999, Emax=999999999,
- setflags=[], settraps=[])
+ capitals=1, flags=[], traps=[])
>>> setcontext(myothercontext)
>>> Decimal(1) / Decimal(7)
Decimal("0.142857142857142857142857142857142857142857142857142857142857")
@@ -236,21 +236,21 @@
Decimal("3.14159292")
>>> getcontext()
Context(prec=9, rounding=ROUND_HALF_EVEN, Emin=-999999999, Emax=999999999,
- setflags=['Inexact', 'Rounded'], settraps=[])
+ capitals=1, flags=[Inexact, Rounded], traps=[])
\end{verbatim}
-The \var{setflags} entry shows that the rational approximation to
+The \var{flags} entry shows that the rational approximation to
\constant{Pi} was rounded (digits beyond the context precision were thrown
away) and that the result is inexact (some of the discarded digits were
non-zero).
-Individual traps are set using the dictionary in the \member{trap_enablers}
+Individual traps are set using the dictionary in the \member{traps}
field of a context:
\begin{verbatim}
>>> Decimal(1) / Decimal(0)
Decimal("Infinity")
->>> getcontext().trap_enablers[DivisionByZero] = 1
+>>> getcontext().traps[DivisionByZero] = 1
>>> Decimal(1) / Decimal(0)
Traceback (most recent call last):
@@ -264,14 +264,14 @@
\begin{verbatim}
>>> getcontext.clear_flags()
->>> for sig in getcontext().trap_enablers:
-... getcontext().trap_enablers[sig] = 1
+>>> for sig in getcontext().traps:
+... getcontext().traps[sig] = 1
->>> getcontext().trap_enablers.update({Rounded:0, Inexact:0, Subnormal:0})
+>>> getcontext().traps.update({Rounded:0, Inexact:0, Subnormal:0})
>>> getcontext()
Context(prec=9, rounding=ROUND_HALF_EVEN, Emin=-999999999, Emax=999999999,
- setflags=[], settraps=['Clamped', 'Underflow', 'InvalidOperation',
- 'DivisionByZero', 'Overflow'])
+ capitals=1, flags=[], traps=[Clamped, Underflow,
+ InvalidOperation, DivisionByZero, Overflow])
\end{verbatim}
Applications typically set the context once at the beginning of a program
@@ -489,7 +489,7 @@
In addition to the three supplied contexts, new contexts can be created
with the \class{Context} constructor.
-\begin{classdesc}{Context}{prec=None, rounding=None, trap_enablers=None,
+\begin{classdesc}{Context}{prec=None, rounding=None, traps=None,
flags=None, Emin=None, Emax=None, capitals=1}
Creates a new context. If a field is not specified or is \constant{None},
the default values are copied from the \constant{DefaultContext}. If the
@@ -508,7 +508,7 @@
\constant{ROUND_HALF_UP} (away from zero), or
\constant{ROUND_UP} (away from zero).
- The \var{trap_enablers} and \var{flags} fields are mappings from signals
+ The \var{traps} and \var{flags} fields are mappings from signals
to either \constant{0} or \constant{1}.
The \var{Emin} and \var{Emax} fields are integers specifying the outer
@@ -839,7 +839,7 @@
# Set applicationwide defaults for all threads about to be launched
DefaultContext.prec=12
DefaultContext.rounding=ROUND_DOWN
-DefaultContext.trap_enablers=dict.fromkeys(Signals, 0)
+DefaultContext.traps=dict.fromkeys(Signals, 0)
setcontext(DefaultContext)
# Now start all of the threads
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,
)
diff --git a/Lib/test/test_decimal.py b/Lib/test/test_decimal.py
index dc202f3..6354063 100644
--- a/Lib/test/test_decimal.py
+++ b/Lib/test/test_decimal.py
@@ -38,7 +38,7 @@
# Tests are built around these assumed context defaults
DefaultContext.prec=9
DefaultContext.rounding=ROUND_HALF_EVEN
-DefaultContext.trap_enablers=dict.fromkeys(Signals, 0)
+DefaultContext.traps=dict.fromkeys(Signals, 0)
setcontext(DefaultContext)
@@ -105,8 +105,8 @@
def setUp(self):
global dir
self.context = Context()
- for key in DefaultContext.trap_enablers.keys():
- DefaultContext.trap_enablers[key] = 1
+ for key in DefaultContext.traps.keys():
+ DefaultContext.traps[key] = 1
self.ignore_list = ['#']
# Basically, a # means return NaN InvalidOperation.
# Different from a sNaN in trim
@@ -120,8 +120,8 @@
def tearDown(self):
"""Cleaning up enviroment."""
# leaving context in original state
- for key in DefaultContext.trap_enablers.keys():
- DefaultContext.trap_enablers[key] = 0
+ for key in DefaultContext.traps.keys():
+ DefaultContext.traps[key] = 0
return
def eval_file(self, file):
@@ -205,9 +205,9 @@
theirexceptions = [ErrorNames[x.lower()] for x in exceptions]
for exception in Signals:
- self.context.trap_enablers[exception] = 1 #Catch these bugs...
+ self.context.traps[exception] = 1 #Catch these bugs...
for exception in theirexceptions:
- self.context.trap_enablers[exception] = 0
+ self.context.traps[exception] = 0
for i, val in enumerate(valstemp):
if val.count("'") % 2 == 1:
quote = 1 - quote
@@ -221,7 +221,7 @@
if fname in ('to_sci_string', 'to_eng_string'):
if EXTENDEDERRORTEST:
for error in theirexceptions:
- self.context.trap_enablers[error] = 1
+ self.context.traps[error] = 1
try:
funct(self.context.create_decimal(v))
except error:
@@ -231,7 +231,7 @@
(e, s, error))
else:
self.fail("Did not raise %s in %s" % (error, s))
- self.context.trap_enablers[error] = 0
+ self.context.traps[error] = 0
v = self.context.create_decimal(v)
else:
v = Decimal(v)
@@ -241,7 +241,7 @@
if EXTENDEDERRORTEST and fname not in ('to_sci_string', 'to_eng_string'):
for error in theirexceptions:
- self.context.trap_enablers[error] = 1
+ self.context.traps[error] = 1
try:
funct(*vals)
except error:
@@ -251,7 +251,7 @@
(e, s, error))
else:
self.fail("Did not raise %s in %s" % (error, s))
- self.context.trap_enablers[error] = 0
+ self.context.traps[error] = 0
try:
result = str(funct(*vals))
if fname == 'same_quantum':
@@ -263,7 +263,7 @@
raise
myexceptions = self.getexceptions()
- self.resetflags()
+ self.context.clear_flags()
myexceptions.sort()
theirexceptions.sort()
@@ -282,10 +282,6 @@
L.append(exception)
return L
- def resetflags(self):
- for exception in Signals:
- self.context.flags[exception] = 0
-
def change_precision(self, prec):
self.context.prec = prec
def change_rounding_method(self, rounding):