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<H3>
<BR>
4.7.1.3 StreamReader Objects 
</H3>

<P>
The <tt class="class">StreamReader</tt> class is a subclass of <tt class="class">Codec</tt> and
defines the following methods which every stream reader must define in
order to be compatible to the Python codec registry.

<P>
<dl><dt><b><a name='l2h-667'><tt class='class'>StreamReader</tt></a></b> (<var>stream</var><big>[</big><var>, errors</var><big>]</big>)
<dd>
  Constructor for a <tt class="class">StreamReader</tt> instance. 

<P>
All stream readers must provide this constructor interface. They are
  free to add additional keyword arguments, but only the ones defined
  here are used by the Python codec registry.

<P>
<var>stream</var> must be a file-like object open for reading (binary)
  data.

<P>
The <tt class="class">StreamReader</tt> may implement different error handling
  schemes by providing the <var>errors</var> keyword argument. These
  parameters are defined:

<P>

<UL>
<LI><code>'strict'</code> Raise <tt class="exception">ValueError</tt> (or a subclass);
                          this is the default.
</LI>
<LI><code>'ignore'</code> Ignore the character and continue with the next.
</LI>
<LI><code>'replace'</code> Replace with a suitable replacement character.
  
</LI>
</UL>
</dl>

<P>
<dl><dt><b><a name='l2h-668'><tt class='method'>read</tt></a></b> (<big>[</big><var>size</var><big>]</big>)
<dd>
  Decodes data from the stream and returns the resulting object.

<P>
<var>size</var> indicates the approximate maximum number of bytes to read
  from the stream for decoding purposes. The decoder can modify this
  setting as appropriate. The default value -1 indicates to read and
  decode as much as possible.  <var>size</var> is intended to prevent having
  to decode huge files in one step.

<P>
The method should use a greedy read strategy meaning that it should
  read as much data as is allowed within the definition of the encoding
  and the given size, e.g.  if optional encoding endings or state
  markers are available on the stream, these should be read too.
</dl>

<P>
<dl><dt><b><a name='l2h-669'><tt class='method'>readline</tt></a></b> (<var>[size]</var>)
<dd>
  Read one line from the input stream and return the
  decoded data.

<P>
Note: Unlike the <tt class="method">readlines()</tt> method, this method inherits
  the line breaking knowledge from the underlying stream's
  <tt class="method">readline()</tt> method - there is currently no support for line
  breaking using the codec decoder due to lack of line buffering.
  Sublcasses should however, if possible, try to implement this method
  using their own knowledge of line breaking.

<P>
<var>size</var>, if given, is passed as size argument to the stream's
  <tt class="method">readline()</tt> method.
</dl>

<P>
<dl><dt><b><a name='l2h-670'><tt class='method'>readlines</tt></a></b> (<var>[sizehint]</var>)
<dd>
  Read all lines available on the input stream and return them as list
  of lines.

<P>
Line breaks are implemented using the codec's decoder method and are
  included in the list entries.

<P>
<var>sizehint</var>, if given, is passed as <var>size</var> argument to the
  stream's <tt class="method">read()</tt> method.
</dl>

<P>
<dl><dt><b><a name='l2h-671'><tt class='method'>reset</tt></a></b> ()
<dd>
  Resets the codec buffers used for keeping state.

<P>
Note that no stream repositioning should take place.  This method is
  primarily intended to be able to recover from decoding errors.
</dl>

<P>
In addition to the above methods, the <tt class="class">StreamReader</tt> must also
inherit all other methods and attribute from the underlying stream.

<P>
The next two base classes are included for convenience. They are not
needed by the codec registry, but may provide useful in practice.

<P>

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