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\section{\module{UserDict} ---
Class wrapper for dictionary objects}
\declaremodule{standard}{UserDict}
\modulesynopsis{Class wrapper for dictionary objects.}
This module defines a class that acts as a wrapper around
dictionary objects. It is a useful base class for
your own dictionary-like classes, which can inherit from
them and override existing methods or add new ones. In this way one
can add new behaviours to dictionaries.
The \module{UserDict} module defines the \class{UserDict} class:
\begin{classdesc}{UserDict}{\optional{intialdata}}
Return a class instance that simulates a dictionary. The instance's
contents are kept in a regular dictionary, which is accessible via the
\member{data} attribute of \class{UserDict} instances. If
\var{initialdata} is provided, \member{data} is initialized with its
contents; note that a reference to \var{initialdata} will not be kept,
allowing it be used used for other purposes.
\end{classdesc}
In addition to supporting the methods and operations of mappings (see
section \ref{typesmapping}), \class{UserDict} instances provide the
following attribute:
\begin{memberdesc}{data}
A real dictionary used to store the contents of the \class{UserDict}
class.
\end{memberdesc}
\section{\module{UserList} ---
Class wrapper for list objects}
\declaremodule{standard}{UserList}
\modulesynopsis{Class wrapper for list objects.}
This module defines a class that acts as a wrapper around
list objects. It is a useful base class for
your own list-like classes, which can inherit from
them and override existing methods or add new ones. In this way one
can add new behaviours to lists.
The \module{UserList} module defines the \class{UserList} class:
\begin{classdesc}{UserList}{\optional{list}}
Return a class instance that simulates a list. The instance's
contents are kept in a regular list, which is accessible via the
\member{data} attribute of \class{UserList} instances. The instance's
contents are initially set to a copy of \var{list}, defaulting to the
empty list \code{[]}. \var{list} can be either a regular Python list,
or an instance of \class{UserList} (or a subclass).
\end{classdesc}
In addition to supporting the methods and operations of mutable
sequences (see section \ref{typesseq}), \class{UserList} instances
provide the following attribute:
\begin{memberdesc}{data}
A real Python list object used to store the contents of the
\class{UserList} class.
\end{memberdesc}
\section{\module{UserString} ---
Class wrapper for string objects}
\declaremodule{standard}{UserString}
\modulesynopsis{Class wrapper for string objects.}
\moduleauthor{Peter Funk}{pf@artcom-gmbh.de}
\sectionauthor{Peter Funk}{pf@artcom-gmbh.de}
This module defines a class that acts as a wrapper around
string objects. It is a useful base class for
your own string-like classes, which can inherit from
them and override existing methods or add new ones. In this way one
can add new behaviours to strings.
The \module{UserString} module defines the \class{UserString} class:
\begin{classdesc}{UserString}{\optional{sequence}}
Return a class instance that simulates a string or a Unicode string object.
The instance's content is kept in a regular string or Unicode string
object, which is accessible via the
\member{data} attribute of \class{UserString} instances. The instance's
contents are initially set to a copy of \var{sequence}.
\var{sequence} can be either a regular Python string or Unicode string,
an instance of \class{UserString} (or a subclass) or an arbitrary sequence
which can be converted into a string.
\end{classdesc}
In addition to supporting the methods and operations of string or
Unicode objects (see section \ref{typesseq}), \class{UserString} instances
provide the following attribute:
\begin{memberdesc}{data}
A real Python string or Unicode object used to store the content of the
\class{UserString} class.
\end{memberdesc}
\begin{classdesc}{MutableString}{\optional{sequence}}
This class is derived from the \class{UserString} above and redefines
strings to be \emph{mutable}. Mutable strings can't be used as
dictionary keys, because dictionaries require \emph{immutable} objects as
keys. The main intention of this class is to serve as an educational
example for inheritance and necessity to remove (override) the
\function{__hash__} method in order to trap attempts to use a
mutable object as dictionary key, which would be otherwise very
errorprone and hard to track down.
\end{classdesc}
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