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Bug #801349: document that start/stop/step slice arguments can be None

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This commit is contained in:
Georg Brandl 2006-02-19 00:12:42 +00:00
parent b2699b242d
commit 1dc5a84aee
2 changed files with 7 additions and 6 deletions
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11
Doc/lib/libstdtypes.tex
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@ -532,9 +532,10 @@ In Python 2.3 and beyond, \var{x} may be a string of any length.
\item[(4)] The slice of \var{s} from \var{i} to \var{j} is defined as
the sequence of items with index \var{k} such that \code{\var{i} <=
\var{k} < \var{j}}. If \var{i} or \var{j} is greater than
\code{len(\var{s})}, use \code{len(\var{s})}. If \var{i} is omitted,
use \code{0}. If \var{j} is omitted, use \code{len(\var{s})}. If
\var{i} is greater than or equal to \var{j}, the slice is empty.
\code{len(\var{s})}, use \code{len(\var{s})}. If \var{i} is omitted
or \code{None}, use \code{0}. If \var{j} is omitted or \code{None},
use \code{len(\var{s})}. If \var{i} is greater than or equal to \var{j},
the slice is empty.
\item[(5)] The slice of \var{s} from \var{i} to \var{j} with step
\var{k} is defined as the sequence of items with index
@ -543,9 +544,9 @@ In Python 2.3 and beyond, \var{x} may be a string of any length.
are \code{i}, \code{i+k}, \code{i+2*k}, \code{i+3*k} and so on, stopping when
\var{j} is reached (but never including \var{j}). If \var{i} or \var{j}
is greater than \code{len(\var{s})}, use \code{len(\var{s})}. If
\var{i} or \var{j} are omitted then they become ``end'' values
\var{i} or \var{j} are omitted or \code{None}, they become ``end'' values
(which end depends on the sign of \var{k}). Note, \var{k} cannot
be zero.
be zero. If \var{k} is \code{None}, it is treated like \code{1}.
\item[(6)] If \var{s} and \var{t} are both strings, some Python
implementations such as CPython can usually perform an in-place optimization

2
Python/ceval.c
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@ -3905,7 +3905,7 @@ _PyEval_SliceIndex(PyObject *v, Py_ssize_t *pi)
}
} else {
PyErr_SetString(PyExc_TypeError,
"slice indices must be integers");
"slice indices must be integers or None");
return 0;
}
*pi = x;