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| -rw-r--r-- | Misc/NEWS | 23 |
1 files changed, 23 insertions, 0 deletions
@@ -57,6 +57,29 @@ Type/class unification and new-style classes Core and builtins +- There's a new warning category, FutureWarning. This is used to warn + about a number of situations where the value or sign of an integer + result will change in Python 2.4 as a result of PEP 237 (integer + unification). The warnings implement stage B0 mentioned in that + PEP. The warnings are about the following situations: + + - Octal and hex literals without 'L' prefix in the inclusive range + [0x80000000..0xffffffff]; these are currently negative ints, but + in Python 2.4 they will be positive longs with the same bit + pattern. + + - Left shifts on integer values that cause the outcome to lose + bits or have a different sign than the left operand. To be + precise: x<<n where this currently doesn't yield the same value + as long(x)<<n; in Python 2.4, the outcome will be long(x)<<n. + + - Conversions from ints to string that show negative values as + unsigned ints in the inclusive range [0x80000000..0xffffffff]; + this affects the functions hex() and oct(), and the string + formatting codes %u, %o, %x, and %X. In Python 2.4, these will + show signed values (e.g. hex(-1) currently returns "0xffffffff"; + in Python 2.4 it will return "-0x1"). + - When multiplying very large integers, a version of the so-called Karatsuba algorithm is now used. This is most effective if the inputs have roughly the same size. If they both have about N digits, |