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| 54 | <H2><A NAME="SECTION0052820000000000000000"></A><A NAME="subclassing-reprs"></A> |
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| 56 | 3.28.2 Subclassing Repr Objects |
| 57 | </H2> |
| 58 | |
| 59 | <P> |
| 60 | The use of dynamic dispatching by <tt class="method">Repr.repr1()</tt> allows |
| 61 | subclasses of <tt class="class">Repr</tt> to add support for additional built-in |
| 62 | object types or to modify the handling of types already supported. |
| 63 | This example shows how special support for file objects could be |
| 64 | added: |
| 65 | |
| 66 | <P> |
| 67 | <div class="verbatim"><pre> |
| 68 | import repr |
| 69 | import sys |
| 70 | |
| 71 | class MyRepr(repr.Repr): |
| 72 | def repr_file(self, obj, level): |
| 73 | if obj.name in ['<stdin>', '<stdout>', '<stderr>']: |
| 74 | return obj.name |
| 75 | else: |
| 76 | return `obj` |
| 77 | |
| 78 | aRepr = MyRepr() |
| 79 | print aRepr.repr(sys.stdin) # prints '<stdin>' |
| 80 | </pre></div> |
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