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Reordering of __new__ to minimize isinstance() calls to most 

used types. Thanks Mark Dickinson.
This commit is contained in:
Facundo Batista 2007-11-30 17:15:25 +00:00
parent 025c347d61
commit 0d157a0154
1 changed files with 56 additions and 55 deletions
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111
Lib/decimal.py
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@ -540,21 +540,47 @@ class Decimal(object):
# digits. # digits.
self = object.__new__(cls) self = object.__new__(cls)
self._is_special = False
# From an internal working value # From a string
if isinstance(value, _WorkRep): # REs insist on real strings, so we can too.
self._sign = value.sign if isinstance(value, basestring):
self._int = str(value.int) m = _parser(value)
self._exp = int(value.exp) if m is None:
return self if context is None:
context = getcontext()
return context._raise_error(ConversionSyntax,
"Invalid literal for Decimal: %r" % value)
# From another decimal if m.group('sign') == "-":
if isinstance(value, Decimal): self._sign = 1
self._exp = value._exp else:
self._sign = value._sign self._sign = 0
self._int = value._int intpart = m.group('int')
self._is_special = value._is_special if intpart is not None:
# finite number
fracpart = m.group('frac')
exp = int(m.group('exp') or '0')
if fracpart is not None:
self._int = (intpart+fracpart).lstrip('0') or '0'
self._exp = exp - len(fracpart)
else:
self._int = intpart.lstrip('0') or '0'
self._exp = exp
self._is_special = False
else:
diag = m.group('diag')
if diag is not None:
# NaN
self._int = diag.lstrip('0')
if m.group('signal'):
self._exp = 'N'
else:
self._exp = 'n'
else:
# infinity
self._int = '0'
self._exp = 'F'
self._is_special = True
return self return self
# From an integer # From an integer
@ -565,6 +591,23 @@ class Decimal(object):
self._sign = 1 self._sign = 1
self._exp = 0 self._exp = 0
self._int = str(abs(value)) self._int = str(abs(value))
self._is_special = False
return self
# From another decimal
if isinstance(value, Decimal):
self._exp = value._exp
self._sign = value._sign
self._int = value._int
self._is_special = value._is_special
return self
# From an internal working value
if isinstance(value, _WorkRep):
self._sign = value.sign
self._int = str(value.int)
self._exp = int(value.exp)
self._is_special = False
return self return self
# tuple/list conversion (possibly from as_tuple()) # tuple/list conversion (possibly from as_tuple())
@ -616,48 +659,6 @@ class Decimal(object):
raise TypeError("Cannot convert float to Decimal. " + raise TypeError("Cannot convert float to Decimal. " +
"First convert the float to a string") "First convert the float to a string")
# From a string
# REs insist on real strings, so we can too.
if isinstance(value, basestring):
m = _parser(value)
if m is None:
if context is None:
context = getcontext()
return context._raise_error(ConversionSyntax,
"Invalid literal for Decimal: %r" % value)
if m.group('sign') == "-":
self._sign = 1
else:
self._sign = 0
intpart = m.group('int')
if intpart is not None:
# finite number
fracpart = m.group('frac')
exp = int(m.group('exp') or '0')
if fracpart is not None:
self._int = (intpart+fracpart).lstrip('0') or '0'
self._exp = exp - len(fracpart)
else:
self._int = intpart.lstrip('0') or '0'
self._exp = exp
self._is_special = False
else:
diag = m.group('diag')
if diag is not None:
# NaN
self._int = diag.lstrip('0')
if m.group('signal'):
self._exp = 'N'
else:
self._exp = 'n'
else:
# infinity
self._int = '0'
self._exp = 'F'
self._is_special = True
return self
raise TypeError("Cannot convert %r to Decimal" % value) raise TypeError("Cannot convert %r to Decimal" % value)
def _isnan(self): def _isnan(self):