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			44 lines
		
	
	
	
		
			1.5 KiB
		
	
	
	
		
			TeX
		
	
	
	
	
	
			
		
		
	
	
			44 lines
		
	
	
	
		
			1.5 KiB
		
	
	
	
		
			TeX
		
	
	
	
	
	
\section{\module{__builtin__} ---
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         Built-in objects}
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\declaremodule[builtin]{builtin}{__builtin__}
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\modulesynopsis{The module that provides the built-in namespace.}
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This module provides direct access to all `built-in' identifiers of
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Python; for example, \code{__builtin__.open} is the full name for the
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built-in function \function{open()}.  See chapter~\ref{builtin},
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``Built-in Objects.''
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This module is not normally accessed explicitly by most applications,
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but can be useful in modules that provide objects with the same name
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as a built-in value, but in which the built-in of that name is also
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needed.  For example, in a module that wants to implement an
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\function{open()} function that wraps the built-in \function{open()},
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this module can be used directly:
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\begin{verbatim}
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import __builtin__
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def open(path):
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    f = __builtin__.open(path, 'r')
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    return UpperCaser(f)
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class UpperCaser:
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    '''Wrapper around a file that converts output to upper-case.'''
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    def __init__(self, f):
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        self._f = f
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    def read(self, count=-1):
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        return self._f.read(count).upper()
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    # ...
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\end{verbatim}
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As an implementation detail, most modules have the name
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\code{__builtins__} (note the \character{s}) made available as part of
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their globals.  The value of \code{__builtins__} is normally either
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this module or the value of this modules's \member{__dict__}
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attribute.  Since this is an implementation detail, it may not be used
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by alternate implementations of Python.
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