Called to implement assignment to \code{\var{self}[\var{i}:\var{j}]}.
Same notes for \var{i} and \var{j} as for \method{__getslice__()}.
-This method is deprecated. If no \method{__setslice__()} is found, a slice
-object is created instead, and passed to \method{__setitem__()} instead.
+This method is deprecated. If no \method{__setslice__()} is found, a
+slice object is created instead, and passed to \method{__setitem__()}
+instead.
\end{methoddesc}
\begin{methoddesc}[sequence object]{__delslice__}{self, i, j}
Called to implement deletion of \code{\var{self}[\var{i}:\var{j}]}.
Same notes for \var{i} and \var{j} as for \method{__getslice__()}.
-This method is deprecated. If no \method{__delslice__()} is found, a slice
-object is created instead, and passed to \method{__delitem__()} instead.
+This method is deprecated. If no \method{__delslice__()} is found, a
+slice object is created instead, and passed to \method{__delitem__()}
+instead.
\end{methoddesc}
-Notice that these methods are only invoked when a single slice with a single
-colon is used, and the slice method is available. For slice operations
-involving extended slice notation, or in absence of the slice methods,
-\method{__getitem__()}, \method{__setitem__()} or \method{__delitem__()} is
-called with a slice object as argument.
+Notice that these methods are only invoked when a single slice with a
+single colon is used, and the slice method is available. For slice
+operations involving extended slice notation, or in absence of the
+slice methods, \method{__getitem__()}, \method{__setitem__()} or
+\method{__delitem__()} is called with a slice object as argument.
The following example demonstrate how to make your program or module
compatible with earlier versions of Python (assuming that methods
called to implement the binary arithmetic operations (\code{+},
\code{-}, \code{*}, \code{/}, \code{\%},
\function{divmod()}\bifuncindex{divmod},
-\function{pow()}\bifuncindex{pow}, \code{**}, \code{<<}, \code{>>},
-\code{\&}, \code{\^}, \code{|}). For instance, to evaluate the
-expression \var{x}\code{+}\var{y}, where \var{x} is an instance of a
-class that has an \method{__add__()} method,
+\function{pow()}\bifuncindex{pow}, \code{**}, \code{<}\code{<},
+\code{>}\code{>}, \code{\&}, \code{\^}, \code{|}). For instance, to
+evaluate the expression \var{x}\code{+}\var{y}, where \var{x} is an
+instance of a class that has an \method{__add__()} method,
\code{\var{x}.__add__(\var{y})} is called. Note that
\method{__pow__()} should be defined to accept an optional third
argument if the ternary version of the built-in
called to implement the binary arithmetic operations (\code{+},
\code{-}, \code{*}, \code{/}, \code{\%},
\function{divmod()}\bifuncindex{divmod},
-\function{pow()}\bifuncindex{pow}, \code{**}, \code{<<}, \code{>>},
-\code{\&}, \code{\^}, \code{|}) with reflected (swapped) operands. These
-functions are only called if the left operand does not support the
-corresponding operation. For instance, to evaluate the expression
-\var{x}\code{-}\var{y}, where \var{y} is an instance of a class that
-has an \method{__rsub__()} method, \code{\var{y}.__rsub__(\var{x})} is
-called. Note that ternary \function{pow()}\bifuncindex{pow} will not
-try calling \method{__rpow__()} (the coercion rules would become too
+\function{pow()}\bifuncindex{pow}, \code{**}, \code{<}\code{<},
+\code{>}\code{>}, \code{\&}, \code{\^}, \code{|}) with reflected
+(swapped) operands. These functions are only called if the left
+operand does not support the corresponding operation. For instance,
+to evaluate the expression \var{x}\code{-}\var{y}, where \var{y} is an
+instance of a class that has an \method{__rsub__()} method,
+\code{\var{y}.__rsub__(\var{x})} is called. Note that ternary
+\function{pow()}\bifuncindex{pow} will not try calling
+\method{__rpow__()} (the coercion rules would become too
complicated).
\end{methoddesc}
\methodline[numeric object]{__iand__}{self, other}
\methodline[numeric object]{__ixor__}{self, other}
\methodline[numeric object]{__ior__}{self, other}
-These methods are called to implement the augmented arithmetic operations
-(\code{+=}, \code{-=}, \code{*=}, \code{/=}, \code{\%=}, \code{**=},
-\code{<<=}, \code{>>=}, \code{\&=}, \code{\^=}, \code{|=}). These methods
-should attempt to do the operation in-place (modifying \var{self}) and
-return the result (which could be, but does not have to be, \var{self}). If
-a specific method is not defined, the augmented operation falls back to the
-normal methods. For instance, to evaluate the expression
-\var{x}\code{+=}\var{y}, where \var{x} is an instance of a class that has an
-\method{__iadd__()} method, \code{\var{x}.__iadd__(\var{y})} is called. If
-\var{x} is an instance of a class that does not define a \method{__iadd()}
-method, \code{\var{x}.__add__(\var{y})} and \code{\var{y}.__radd__(\var{x})}
-are considered, as with the evaluation of \var{x}\code{+}\var{y}.
-
+These methods are called to implement the augmented arithmetic
+operations (\code{+=}, \code{-=}, \code{*=}, \code{/=}, \code{\%=},
+\code{**=}, \code{<}\code{<=}, \code{>}\code{>=}, \code{\&=},
+\code{\^=}, \code{|=}). These methods should attempt to do the
+operation in-place (modifying \var{self}) and return the result (which
+could be, but does not have to be, \var{self}). If a specific method
+is not defined, the augmented operation falls back to the normal
+methods. For instance, to evaluate the expression
+\var{x}\code{+=}\var{y}, where \var{x} is an instance of a class that
+has an \method{__iadd__()} method, \code{\var{x}.__iadd__(\var{y})} is
+called. If \var{x} is an instance of a class that does not define a
+\method{__iadd()} method, \code{\var{x}.__add__(\var{y})} and
+\code{\var{y}.__radd__(\var{x})} are considered, as with the
+evaluation of \var{x}\code{+}\var{y}.
\end{methoddesc}
\begin{methoddesc}[numeric object]{__neg__}{self}
\methodline[numeric object]{__pos__}{self}
\methodline[numeric object]{__abs__}{self}
\methodline[numeric object]{__invert__}{self}
-Called to implement the unary arithmetic operations (\code{-}, \code{+},
-\function{abs()}\bifuncindex{abs} and \code{\~{}}).
+Called to implement the unary arithmetic operations (\code{-},
+\code{+}, \function{abs()}\bifuncindex{abs} and \code{\~{}}).
\end{methoddesc}
\begin{methoddesc}[numeric object]{__complex__}{self}
\end{methoddesc}
\strong{Coercion rules}: to evaluate \var{x} \var{op} \var{y}, the
-following steps are taken (where \method{__op__()} and
-\method{__rop__()} are the method names corresponding to \var{op},
-e.g., if var{op} is `\code{+}', \method{__add__()} and
+following steps are taken (where \method{__\var{op}__()} and
+\method{__r\var{op}__()} are the method names corresponding to
+\var{op}, e.g., if \var{op} is `\code{+}', \method{__add__()} and
\method{__radd__()} are used). If an exception occurs at any point,
the evaluation is abandoned and exception handling takes over.
\begin{itemize}
-\item[0.] If \var{x} is a string object and op is the modulo operator (\%),
-the string formatting operation is invoked and the remaining steps are
-skipped.
+\item[0.] If \var{x} is a string object and \var{op} is the modulo
+ operator (\%), the string formatting operation is invoked and
+ the remaining steps are skipped.
\item[1.] If \var{x} is a class instance:
\item[1b.] If neither \var{x} nor \var{y} is a class instance
after coercion, go to step 3.
- \item[1c.] If \var{x} has a method \method{__op__()}, return
- \code{\var{x}.__op__(\var{y})}; otherwise, restore \var{x} and
+ \item[1c.] If \var{x} has a method \method{__\var{op}__()}, return
+ \code{\var{x}.__\var{op}__(\var{y})}; otherwise, restore \var{x} and
\var{y} to their value before step 1a.
\end{itemize}
\item[2b.] If neither \var{x} nor \var{y} is a class instance
after coercion, go to step 3.
- \item[2b.] If \var{y} has a method \method{__rop__()}, return
- \code{\var{y}.__rop__(\var{x})}; otherwise, restore \var{x}
- and \var{y} to their value before step 2a.
+ \item[2b.] If \var{y} has a method \method{__r\var{op}__()},
+ return \code{\var{y}.__r\var{op}__(\var{x})}; otherwise,
+ restore \var{x} and \var{y} to their value before step 2a.
\end{itemize}
\begin{itemize}
- \item[3a.] If op is `\code{+}' and \var{x} is a sequence,
- sequence concatenation is invoked.
+ \item[3a.] If \var{op} is `\code{+}' and \var{x} is a
+ sequence, sequence concatenation is invoked.
- \item[3b.] If op is `\code{*}' and one operand is a sequence
- and the other an integer, sequence repetition is invoked.
+ \item[3b.] If \var{op} is `\code{*}' and one operand is a
+ sequence and the other an integer, sequence repetition is
+ invoked.
\item[3c.] Otherwise, both operands must be numbers; they are
coerced to a common type if possible, and the numeric