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			336 lines
		
	
	
	
		
			9.3 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
			
		
		
	
	
			336 lines
		
	
	
	
		
			9.3 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
"""Parse a Python file and retrieve classes and methods.
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Parse enough of a Python file to recognize class and method
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definitions and to find out the superclasses of a class.
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The interface consists of a single function:
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	readmodule(module, path)
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module is the name of a Python module, path is an optional list of
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directories where the module is to be searched.  If present, path is
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prepended to the system search path sys.path.
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The return value is a dictionary.  The keys of the dictionary are
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the names of the classes defined in the module (including classes
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that are defined via the from XXX import YYY construct).  The values
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are class instances of the class Class defined here.
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A class is described by the class Class in this module.  Instances
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of this class have the following instance variables:
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	name -- the name of the class
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	super -- a list of super classes (Class instances)
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	methods -- a dictionary of methods
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	file -- the file in which the class was defined
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	lineno -- the line in the file on which the class statement occurred
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The dictionary of methods uses the method names as keys and the line
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numbers on which the method was defined as values.
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If the name of a super class is not recognized, the corresponding
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entry in the list of super classes is not a class instance but a
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string giving the name of the super class.  Since import statements
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are recognized and imported modules are scanned as well, this
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shouldn't happen often.
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BUGS
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- Continuation lines are not dealt with at all.
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- While triple-quoted strings won't confuse it, lines that look like
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  def, class, import or "from ... import" stmts inside backslash-continued
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  single-quoted strings are treated like code.  The expense of stopping
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  that isn't worth it.
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- Code that doesn't pass tabnanny or python -t will confuse it, unless
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  you set the module TABWIDTH vrbl (default 8) to the correct tab width
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  for the file.
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PACKAGE RELATED BUGS
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- If you have a package and a module inside that or another package
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  with the same name, module caching doesn't work properly since the
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  key is the base name of the module/package.
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- The only entry that is returned when you readmodule a package is a
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  __path__ whose value is a list which confuses certain class browsers.
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- When code does:
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  from package import subpackage
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  class MyClass(subpackage.SuperClass):
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    ...
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  It can't locate the parent.  It probably needs to have the same
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  hairy logic that the import locator already does.  (This logic
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  exists coded in Python in the freeze package.)
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"""
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import os
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import sys
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import imp
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import re
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import string
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TABWIDTH = 8
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_getnext = re.compile(r"""
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    (?P<String>
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       \""" [^"\\]* (?:
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			(?: \\. | "(?!"") )
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			[^"\\]*
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		    )*
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       \"""
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    |   ''' [^'\\]* (?:
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			(?: \\. | '(?!'') )
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			[^'\\]*
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		    )*
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	'''
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    )
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|   (?P<Method>
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	^
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	(?P<MethodIndent> [ \t]* )
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	def [ \t]+
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	(?P<MethodName> [a-zA-Z_] \w* )
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	[ \t]* \(
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    )
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|   (?P<Class>
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	^
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	(?P<ClassIndent> [ \t]* )
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	class [ \t]+
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	(?P<ClassName> [a-zA-Z_] \w* )
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	[ \t]*
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	(?P<ClassSupers> \( [^)\n]* \) )?
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	[ \t]* :
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    )
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|   (?P<Import>
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	^ import [ \t]+
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	(?P<ImportList> [^#;\n]+ )
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    )
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|   (?P<ImportFrom>
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	^ from [ \t]+
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	(?P<ImportFromPath>
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	    [a-zA-Z_] \w*
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	    (?:
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		[ \t]* \. [ \t]* [a-zA-Z_] \w*
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	    )*
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	)
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	[ \t]+
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	import [ \t]+
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	(?P<ImportFromList> [^#;\n]+ )
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    )
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""", re.VERBOSE | re.DOTALL | re.MULTILINE).search
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_modules = {}                           # cache of modules we've seen
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# each Python class is represented by an instance of this class
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class Class:
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	'''Class to represent a Python class.'''
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	def __init__(self, module, name, super, file, lineno):
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		self.module = module
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		self.name = name
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		if super is None:
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			super = []
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		self.super = super
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		self.methods = {}
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		self.file = file
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		self.lineno = lineno
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	def _addmethod(self, name, lineno):
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		self.methods[name] = lineno
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class Function(Class):
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	'''Class to represent a top-level Python function'''
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	def __init__(self, module, name, file, lineno):
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		Class.__init__(self, module, name, None, file, lineno)
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	def _addmethod(self, name, lineno):
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		assert 0, "Function._addmethod() shouldn't be called"
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def readmodule(module, path=[], inpackage=0):
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	'''Backwards compatible interface.
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	Like readmodule_ex() but strips Function objects from the
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	resulting dictionary.'''
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	dict = readmodule_ex(module, path, inpackage)
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	res = {}
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	for key, value in dict.items():
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		if not isinstance(value, Function):
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			res[key] = value
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	return res
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def readmodule_ex(module, path=[], inpackage=0):
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	'''Read a module file and return a dictionary of classes.
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	Search for MODULE in PATH and sys.path, read and parse the
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	module and return a dictionary with one entry for each class
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	found in the module.'''
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	dict = {}
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	i = string.rfind(module, '.')
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	if i >= 0:
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		# Dotted module name
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		package = string.strip(module[:i])
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		submodule = string.strip(module[i+1:])
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		parent = readmodule(package, path, inpackage)
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		child = readmodule(submodule, parent['__path__'], 1)
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		return child
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	if _modules.has_key(module):
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		# we've seen this module before...
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		return _modules[module]
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	if module in sys.builtin_module_names:
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		# this is a built-in module
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		_modules[module] = dict
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		return dict
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	# search the path for the module
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	f = None
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	if inpackage:
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		try:
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			f, file, (suff, mode, type) = \
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				imp.find_module(module, path)
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		except ImportError:
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			f = None
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	if f is None:
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		fullpath = list(path) + sys.path
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		f, file, (suff, mode, type) = imp.find_module(module, fullpath)
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	if type == imp.PKG_DIRECTORY:
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		dict['__path__'] = [file]
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		_modules[module] = dict
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		path = [file] + path
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		f, file, (suff, mode, type) = \
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				imp.find_module('__init__', [file])
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	if type != imp.PY_SOURCE:
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		# not Python source, can't do anything with this module
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		f.close()
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		_modules[module] = dict
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		return dict
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	_modules[module] = dict
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	imports = []
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	classstack = []	# stack of (class, indent) pairs
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	src = f.read()
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	f.close()
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	# To avoid having to stop the regexp at each newline, instead
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	# when we need a line number we simply string.count the number of
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	# newlines in the string since the last time we did this; i.e.,
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	#    lineno = lineno + \
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	#             string.count(src, '\n', last_lineno_pos, here)
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	#    last_lineno_pos = here
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	countnl = string.count
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	lineno, last_lineno_pos = 1, 0
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	i = 0
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	while 1:
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		m = _getnext(src, i)
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		if not m:
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			break
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		start, i = m.span()
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		if m.start("Method") >= 0:
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			# found a method definition or function
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			thisindent = _indent(m.group("MethodIndent"))
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			meth_name = m.group("MethodName")
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			lineno = lineno + \
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				 countnl(src, '\n',
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					 last_lineno_pos, start)
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			last_lineno_pos = start
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			# close all classes indented at least as much
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			while classstack and \
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			      classstack[-1][1] >= thisindent:
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				del classstack[-1]
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			if classstack:
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				# it's a class method
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				cur_class = classstack[-1][0]
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				cur_class._addmethod(meth_name, lineno)
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			else:
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				# it's a function
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				f = Function(module, meth_name,
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					     file, lineno)
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				dict[meth_name] = f
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		elif m.start("String") >= 0:
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			pass
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		elif m.start("Class") >= 0:
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			# we found a class definition
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			thisindent = _indent(m.group("ClassIndent"))
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			# close all classes indented at least as much
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			while classstack and \
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			      classstack[-1][1] >= thisindent:
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				del classstack[-1]
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			lineno = lineno + \
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				 countnl(src, '\n', last_lineno_pos, start)
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			last_lineno_pos = start
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			class_name = m.group("ClassName")
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			inherit = m.group("ClassSupers")
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			if inherit:
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				# the class inherits from other classes
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				inherit = string.strip(inherit[1:-1])
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				names = []
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				for n in string.splitfields(inherit, ','):
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					n = string.strip(n)
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					if dict.has_key(n):
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						# we know this super class
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						n = dict[n]
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					else:
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						c = string.splitfields(n, '.')
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						if len(c) > 1:
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							# super class
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							# is of the
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							# form module.class:
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							# look in
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							# module for class
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							m = c[-2]
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							c = c[-1]
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							if _modules.has_key(m):
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								d = _modules[m]
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								if d.has_key(c):
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									n = d[c]
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					names.append(n)
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				inherit = names
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			# remember this class
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			cur_class = Class(module, class_name, inherit,
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					  file, lineno)
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			dict[class_name] = cur_class
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			classstack.append((cur_class, thisindent))
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		elif m.start("Import") >= 0:
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			# import module
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			for n in string.split(m.group("ImportList"), ','):
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				n = string.strip(n)
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				try:
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					# recursively read the imported module
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					d = readmodule(n, path, inpackage)
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				except:
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					##print 'module', n, 'not found'
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					pass
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		elif m.start("ImportFrom") >= 0:
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			# from module import stuff
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			mod = m.group("ImportFromPath")
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			names = string.split(m.group("ImportFromList"), ',')
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			try:
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				# recursively read the imported module
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				d = readmodule(mod, path, inpackage)
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			except:
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				##print 'module', mod, 'not found'
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				continue
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			# add any classes that were defined in the
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			# imported module to our name space if they
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			# were mentioned in the list
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			for n in names:
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				n = string.strip(n)
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				if d.has_key(n):
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					dict[n] = d[n]
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				elif n == '*':
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					# only add a name if not
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					# already there (to mimic what
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					# Python does internally)
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					# also don't add names that
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					# start with _
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					for n in d.keys():
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						if n[0] != '_' and \
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						   not dict.has_key(n):
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							dict[n] = d[n]
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		else:
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			assert 0, "regexp _getnext found something unexpected"
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	return dict
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def _indent(ws, _expandtabs=string.expandtabs):
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	return len(_expandtabs(ws, TABWIDTH))
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