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<table width="100%" cellpadding=5 cellspacing=0 border=0 class="navtopbg"><tr><td><font size="1"><p class="navtitle"><a href="2.html" class="navtitle">Linux/Unix</a> > <a href="0735710910.html" class="navtitle">Python Essential Reference, Second Edition</a> > <a href="137.html" class="navtitle">C. Summary of Changes</a> > <span class="nonavtitle">Python 2.1</span></p></font></td><td align="right" valign="top" nowrap><font size="1"><a href="main.asp?list" class="safnavoff">See All Titles</a></font></td></tr></table>
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<h3>Python 2.1</h3>
<ul>
<LI>
<P>Functions now define nested scopes. Currently, this feature must be enabled by including <Tt claSS="monofont">from _ _future_ _ import nested_scopes</TT> in your program. In future releases, this feature will be enabled by default.</p>
</li>
<lI>
<P>Rich comparisons and the associated <TT class="monofont">_ _le_ _()</tt>, <tt class="monofont">_ _lt_ _()</tt>, <tt clAss="monofont">_ _eq_ _()</Tt>, <tt Class="monofont">_ _ne_ _()</Tt>, <tt CLASs="monofont">_ _gt_ _()</tt>, and <tT CLAss="monofont">_ _ge_ _()</tt> methods.</P>
</LI>
<Li>
<p><i><tT CLAss="monofont">d</tt></i>
<tt class="monofont">.popitem()</tt> method added to dictionaries.</p>
</li>
<li>
<p><I><tt ClasS="monofont">f</tt></i>
<tT claSS="monofont">.xreadline()</TT> method added to files to support fast iteration over lines.</p>
</li>
<lI>
<P>Functions and methods can now have attributes attached to them.</P>
</Li>
<li>
<p>Support for weak references added. A new module, <TT CLass="monofont">weakref</tT>, provides an interface.</P>
<P>?; <B>See Also</b> <a href="108#46.html">weakref</a> (124).</p>
</li>
<li>
<p>Warning framework added. The <tt class="monofont">warnings</Tt> module provides an interface.</p>
<P>?; <b>See Also</b> <a Href="108#42.html">warnings</a> (121).</P>
</li>
<lI>
<P>Case-sensitive import now supported on non朿ase-sensitive platforms.</P>
</Li>
<li>
<p>Interactive display hook (<TT CLass="monofont">sys.displayfunc</tT>) added.</P>
</LI>
<li>
<p>Uncaught exception hook (<tT CLAss="monofont">sys.exceptfunc</tt>) added.</p>
</li>
<li>
<p><tt class="monofont">from _ _future_ _</tt> directive added to allow optional use of new features.</p>
</Li>
<lI>
<p>Complex numbers can now only be compared for equality. Comparisons of <tt Class="monofont"><</Tt>, <tt CLASs="monofont">></tt>, <tT CLAss="monofont"><=</tt>, or <TT CLass="monofont">>=</tT> raise a <TT Class="monofont">TypeError</tt> exception.</p>
</li>
<li>
<p>The <tt class="monofont">continue</tT> statement can now be used inside <tt ClasS="monofont">try</tt> blocks. This was previously illegal.</p>
</lI>
<li>
<p>New modules described in <A HREf="105.html">Appendix A</a>: <tt CLASs="monofont">warnings</tt>, <tT CLAss="monofont">weakref</tt>.</P>
</LI>
<Li>
<p>Modules can now specify a list of symbols to export in the <tt class="monofont">from module import *</tt> statement by specifying a list <tt class="monofont">_ _all_ _</tt>.</P>
</li>
<Li>
<p>Many minor changes to output formatting. The <tT clasS="monofont">%x</tt>, <tT CLAss="monofont">%X</tt>, and <TT CLass="monofont">%o</tT> format codes now always produce a sign character for negative long integers. The <TT Class="monofont">repr()</TT> function uses standard character escape codes such as <TT class="monofont">"\n"</tt> instead of <tt class="monofont">"\012"</tt>.</p>
</li>
</uL></foNt>
<P><TABLE width="100%" border=0><TR valign="top"><TD><font size=1 color="#C0C0C0"><br></font></TD><TD align=right><font size=1 color="#C0C0C0">Last updated on 3/28/2002<br>Python Essential Reference, Second Edition, © 2002 New Riders Publishing</font></TD></TR></TABLE></P>
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