67 lines
1.7 KiB
Plaintext
67 lines
1.7 KiB
Plaintext
PEP: 217
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Title: Display Hook for Interactive Use
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Version: $Revision$
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Last-Modified: $Date$
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Author: moshez@zadka.site.co.il (Moshe Zadka)
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Status: Final
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Type: Standards Track
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Content-Type: text/x-rst
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Created: 31-Jul-2000
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Python-Version: 2.1
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Post-History:
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Abstract
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========
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Python's interactive mode is one of the implementation's great
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strengths -- being able to write expressions on the command line
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and get back a meaningful output. However, the output function
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cannot be all things to all people, and the current output
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function too often falls short of this goal. This PEP describes a
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way to provides alternatives to the built-in display function in
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Python, so users will have control over the output from the
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interactive interpreter.
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Interface
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=========
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The current Python solution has worked for many users, and this
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should not break it. Therefore, in the default configuration,
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nothing will change in the REPL loop. To change the way the
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interpreter prints interactively entered expressions, users
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will have to rebind ``sys.displayhook`` to a callable object.
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The result of calling this object with the result of the
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interactively entered expression should be print-able,
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and this is what will be printed on ``sys.stdout``.
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Solution
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========
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The bytecode ``PRINT_EXPR`` will call ``sys.displayhook(POP())``.
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A ``displayhook()`` will be added to the sys builtin module, which is
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equivalent to::
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import __builtin__
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def displayhook(o):
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if o is None:
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return
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__builtin__._ = None
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print `o`
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__builtin__._ = o
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Jython Issues
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=============
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The method ``Py.printResult`` will be similarly changed.
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..
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Local Variables:
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mode: indented-text
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indent-tabs-mode: nil
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End:
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