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<H3><A NAME="SECTION0051461000000000000000">
3.14.6.1 Emulation of <tt class=function>compile()</tt></A>
</H3>

<P>
While many useful operations may take place between parsing and
bytecode generation, the simplest operation is to do nothing.  For
this purpose, using the <tt class=module>parser</tt> module to produce an
intermediate data structure is equivelent to the code

<P>
<dl><dd><pre class=verbatim>
&gt;&gt;&gt; code = compile('a + 5', 'eval')
&gt;&gt;&gt; a = 5
&gt;&gt;&gt; eval(code)
10
</pre></dl>

<P>
The equivelent operation using the <tt class=module>parser</tt> module is somewhat
longer, and allows the intermediate internal parse tree to be retained
as an AST object:

<P>
<dl><dd><pre class=verbatim>
&gt;&gt;&gt; import parser
&gt;&gt;&gt; ast = parser.expr('a + 5')
&gt;&gt;&gt; code = parser.compileast(ast)
&gt;&gt;&gt; a = 5
&gt;&gt;&gt; eval(code)
10
</pre></dl>

<P>
An application which needs both AST and code objects can package this
code into readily available functions:

<P>
<dl><dd><pre class=verbatim>
import parser

def load_suite(source_string):
    ast = parser.suite(source_string)
    code = parser.compileast(ast)
    return ast, code

def load_expression(source_string):
    ast = parser.expr(source_string)
    code = parser.compileast(ast)
    return ast, code
</pre></dl>

<P>
<p>
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