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Merged revisions 60364-60378 via svnmerge from

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  r60364 | neal.norwitz | 2008-01-27 19:09:48 +0100 (Sun, 27 Jan 2008) | 4 lines

  Update the comment and remove the close.  If we close we can't flush anymore.
  We might still need to close after the for loop if flushing 6! times still
  doesn't cause the signal/exception.
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  r60365 | georg.brandl | 2008-01-27 19:14:43 +0100 (Sun, 27 Jan 2008) | 2 lines

  Remove effectless expression statement.
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  r60367 | neal.norwitz | 2008-01-27 19:19:04 +0100 (Sun, 27 Jan 2008) | 1 line

  Try to handle socket.errors properly in is_unavailable
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  r60370 | christian.heimes | 2008-01-27 20:01:45 +0100 (Sun, 27 Jan 2008) | 1 line

  Change isbasestring function as discussed on the cvs list a while ago
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  r60372 | neal.norwitz | 2008-01-27 21:03:13 +0100 (Sun, 27 Jan 2008) | 3 lines

  socket.error doesn't have a headers attribute like ProtocolError.
  Handle that situation where we catch socket.errors.
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  r60375 | georg.brandl | 2008-01-27 21:25:12 +0100 (Sun, 27 Jan 2008) | 2 lines

  Add refcounting extension to build config.
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  r60377 | jeffrey.yasskin | 2008-01-28 00:08:46 +0100 (Mon, 28 Jan 2008) | 6 lines

  Moved Rational._binary_float_to_ratio() to float.as_integer_ratio() because
  it's useful outside of rational numbers.

  This is my first C code that had to do anything significant. Please be more
  careful when looking over it.
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  r60378 | christian.heimes | 2008-01-28 00:34:59 +0100 (Mon, 28 Jan 2008) | 1 line

  Added clear cache methods to clear the internal type lookup cache for ref leak test runs.
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This commit is contained in:
Christian Heimes 2008-01-27 23:50:43 +00:00
parent 7b69c6c3af
commit 2685563583
14 changed files with 254 additions and 71 deletions
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56
Lib/rational.py
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@ -24,60 +24,6 @@ def gcd(a, b):
return a
def _binary_float_to_ratio(x):
"""x -> (top, bot), a pair of ints s.t. x = top/bot.
The conversion is done exactly, without rounding.
bot > 0 guaranteed.
Some form of binary fp is assumed.
Pass NaNs or infinities at your own risk.
>>> _binary_float_to_ratio(10.0)
(10, 1)
>>> _binary_float_to_ratio(0.0)
(0, 1)
>>> _binary_float_to_ratio(-.25)
(-1, 4)
"""
# XXX Move this to floatobject.c with a name like
# float.as_integer_ratio()
if x == 0:
return 0, 1
f, e = math.frexp(x)
signbit = 1
if f < 0:
f = -f
signbit = -1
assert 0.5 <= f < 1.0
# x = signbit * f * 2**e exactly
# Suck up CHUNK bits at a time; 28 is enough so that we suck
# up all bits in 2 iterations for all known binary double-
# precision formats, and small enough to fit in an int.
CHUNK = 28
top = 0
# invariant: x = signbit * (top + f) * 2**e exactly
while f:
f = math.ldexp(f, CHUNK)
digit = trunc(f)
assert digit >> CHUNK == 0
top = (top << CHUNK) | digit
f = f - digit
assert 0.0 <= f < 1.0
e = e - CHUNK
assert top
# Add in the sign bit.
top = signbit * top
# now x = top * 2**e exactly; fold in 2**e
if e>0:
return (top * 2**e, 1)
else:
return (top, 2 ** -e)
_RATIONAL_FORMAT = re.compile(
r'^\s*(?P<sign>[-+]?)(?P<num>\d+)'
r'(?:/(?P<denom>\d+)|\.(?P<decimal>\d+))?\s*$')
@ -162,7 +108,7 @@ def from_float(cls, f):
(cls.__name__, f, type(f).__name__))
if math.isnan(f) or math.isinf(f):
raise TypeError("Cannot convert %r to %s." % (f, cls.__name__))
return cls(*_binary_float_to_ratio(f))
return cls(*f.as_integer_ratio())
@classmethod
def from_decimal(cls, dec):