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<H1><A NAME="SECTION03630000000000000000"></A>
<A NAME="10153"></A>
<BR>
How to Call Methods from Python
</H1>
<P>
Once you have created an object, you call methods on it using normal
Python method calls. The arguments to the method only include the
<A NAME="10154"></A><TT>in</TT> and <TT>inout</TT> arguments, and the return value of the
Python method includes the SIDL return value and the <TT>inout</TT> and
<TT>out</TT> parameters. Hopefully, this will seem natural to Python
programmers. For the following example, the object <TT>obj</TT> has a
method <TT>passeverywhere</TT> with the following SIDL declaration:
<P>
<BR>
<PRE CLASS="verbatim">double passeverywhere( in double d1, out double d2, inout double d3 );
</I></PRE></td></tr></table></blockquote>
<P>
You can see the Python calling signature with <TT><B>print
obj.passeverywhere.__doc__</B></TT>. Here is what that shows for this
example:
<P>
<BR>
<PRE CLASS="verbatim">$ python
>>> import Args.Cdouble
>>> obj = Args.Cdouble.Cdouble()
>>> print obj.passeverywhere.__doc__
passeverywhere(in double d1,
inout double d3)
RETURNS
(double _return,
out double d2,
inout double d3)
</PRE></td></tr></table></blockquote>
<P>
In the method documentation, the SIDL method's return value is called
<TT>_return</TT>; and unless the method is <TT>void</TT>, the return
value always appears first. The fact that <TT>_return</TT> starts with
an underbar should alert you to the fact that it is not a parameter
because parameter names cannot start with an underbar. The document
comments from the SIDL file (i.e. comments enclosed in <TT>/** */</TT>
comments) appear below the Babel generated signature documentation.
<P>
Static methods of a class are available in the Python <TT>x.y.z</TT>
namespace assuming you use the <TT><B>import x.y.z</B></TT> command. Static
methods have documentation just like class methods.
<P>
Examples of calls to SIDL overloaded methods are based on the
<TT>overload_sample.sidl</TT> file shown in Section <A HREF="node107.html#sec:overloading">5.6</A>.
Recall that the file describes three versions of the <TT>getValue</TT> method.
The first takes no arguments, the second takes an integer argument, and the
third takes a boolean. Each is called in the code snippet below:
<P>
<BR>
<PRE CLASS="verbatim">
b1 = 1
i1 = 1
t = Overload.Sample.Sample()
nresult = t.getValue()
iresult = t.getValueInt(i1)
bresult = t.getValueBool(b1)
</PRE></td></tr></table></blockquote>
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