Mercurial > repos > shellac > guppy_basecaller
diff env/lib/python3.7/site-packages/future/builtins/newround.py @ 2:6af9afd405e9 draft
"planemo upload commit 0a63dd5f4d38a1f6944587f52a8cd79874177fc1"
author | shellac |
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date | Thu, 14 May 2020 14:56:58 -0400 |
parents | 26e78fe6e8c4 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/env/lib/python3.7/site-packages/future/builtins/newround.py Thu May 14 14:56:58 2020 -0400 @@ -0,0 +1,102 @@ +""" +``python-future``: pure Python implementation of Python 3 round(). +""" + +from future.utils import PYPY, PY26, bind_method + +# Use the decimal module for simplicity of implementation (and +# hopefully correctness). +from decimal import Decimal, ROUND_HALF_EVEN + + +def newround(number, ndigits=None): + """ + See Python 3 documentation: uses Banker's Rounding. + + Delegates to the __round__ method if for some reason this exists. + + If not, rounds a number to a given precision in decimal digits (default + 0 digits). This returns an int when called with one argument, + otherwise the same type as the number. ndigits may be negative. + + See the test_round method in future/tests/test_builtins.py for + examples. + """ + return_int = False + if ndigits is None: + return_int = True + ndigits = 0 + if hasattr(number, '__round__'): + return number.__round__(ndigits) + + if ndigits < 0: + raise NotImplementedError('negative ndigits not supported yet') + exponent = Decimal('10') ** (-ndigits) + + if PYPY: + # Work around issue #24: round() breaks on PyPy with NumPy's types + if 'numpy' in repr(type(number)): + number = float(number) + + if isinstance(number, Decimal): + d = number + else: + if not PY26: + d = Decimal.from_float(number).quantize(exponent, + rounding=ROUND_HALF_EVEN) + else: + d = from_float_26(number).quantize(exponent, rounding=ROUND_HALF_EVEN) + + if return_int: + return int(d) + else: + return float(d) + + +### From Python 2.7's decimal.py. Only needed to support Py2.6: + +def from_float_26(f): + """Converts a float to a decimal number, exactly. + + Note that Decimal.from_float(0.1) is not the same as Decimal('0.1'). + Since 0.1 is not exactly representable in binary floating point, the + value is stored as the nearest representable value which is + 0x1.999999999999ap-4. The exact equivalent of the value in decimal + is 0.1000000000000000055511151231257827021181583404541015625. + + >>> Decimal.from_float(0.1) + Decimal('0.1000000000000000055511151231257827021181583404541015625') + >>> Decimal.from_float(float('nan')) + Decimal('NaN') + >>> Decimal.from_float(float('inf')) + Decimal('Infinity') + >>> Decimal.from_float(-float('inf')) + Decimal('-Infinity') + >>> Decimal.from_float(-0.0) + Decimal('-0') + + """ + import math as _math + from decimal import _dec_from_triple # only available on Py2.6 and Py2.7 (not 3.3) + + if isinstance(f, (int, long)): # handle integer inputs + return Decimal(f) + if _math.isinf(f) or _math.isnan(f): # raises TypeError if not a float + return Decimal(repr(f)) + if _math.copysign(1.0, f) == 1.0: + sign = 0 + else: + sign = 1 + n, d = abs(f).as_integer_ratio() + # int.bit_length() method doesn't exist on Py2.6: + def bit_length(d): + if d != 0: + return len(bin(abs(d))) - 2 + else: + return 0 + k = bit_length(d) - 1 + result = _dec_from_triple(sign, str(n*5**k), -k) + return result + + +__all__ = ['newround']