ž ¬ÿfn/c@sÊdZddlTdddd„Zdd„Zdd d d „Zd d „Zd d„Zddd„Z dd„Z dd„Z ddd„Z dd„Z Gdd„deƒZGdd„deƒZdS(!uH ast ~~~ The `ast` module helps Python applications to process trees of the Python abstract syntax grammar. The abstract syntax itself might change with each Python release; this module helps to find out programmatically what the current grammar looks like and allows modifications of it. An abstract syntax tree can be generated by passing `ast.PyCF_ONLY_AST` as a flag to the `compile()` builtin function or by using the `parse()` function from this module. The result will be a tree of objects whose classes all inherit from `ast.AST`. A modified abstract syntax tree can be compiled into a Python code object using the built-in `compile()` function. Additionally various helper functions are provided that make working with the trees simpler. The main intention of the helper functions and this module in general is to provide an easy to use interface for libraries that work tightly with the python syntax (template engines for example). :copyright: Copyright 2008 by Armin Ronacher. :license: Python License. i(u*u uexeccCst|||tƒS(un Parse the source into an AST node. Equivalent to compile(source, filename, mode, PyCF_ONLY_AST). (ucompileu PyCF_ONLY_AST(usourceufilenameumode((u(/opt/alt/python33/lib64/python3.3/ast.pyuparsesuparsecsyidd6d d6d d6‰t|tƒr?t|ddƒ}nt|tƒrZ|j}n‡‡fdd†‰ˆ|ƒS( u Safely evaluate an expression node or a string containing a Python expression. The string or node provided may only consist of the following Python literal structures: strings, bytes, numbers, tuples, lists, dicts, sets, booleans, and None. uNoneuTrueuFalseumodeuevalc s2t|ttfƒr|jSt|tƒr2|jSt|tƒrWttˆ|j ƒƒSt|t ƒr|t tˆ|j ƒƒSt|t ƒr¡t tˆ|j ƒƒSt|tƒrÜt‡fdd†t|j|jƒDƒƒSt|tƒr|jˆkrˆ|jSnt|tƒrxt|jttfƒrxt|jtttfƒrxˆ|jƒ}t|jtƒrp| S| Sn t|tƒrt|jttfƒrt|jtttfƒrt|jtttfƒrˆ|jƒ}ˆ|jƒ}t|jtƒr ||S||Sntdt |ƒƒ‚dS(Nc3s-|]#\}}ˆ|ƒˆ|ƒfVqdS(N((u.0ukuv(u_convert(u(/opt/alt/python33/lib64/python3.3/ast.pyu >su1literal_eval.._convert..umalformed node or string: (!u isinstanceuStruBytesusuNumunuTupleutupleumapueltsuListulistuSetusetuDictudictuzipukeysuvaluesuNameuiduUnaryOpuopuUAdduUSubuoperanduBinOpuAdduSuburightuleftu ValueErrorurepr(unodeuoperandulefturight(u_convertu _safe_names(u(/opt/alt/python33/lib64/python3.3/ast.pyu_convert2sB uliteral_eval.._convertNTF(uNoneuTrueuFalseu isinstanceustruparseu Expressionubody(unode_or_string((u_convertu _safe_namesu(/opt/alt/python33/lib64/python3.3/ast.pyu literal_eval&s $u literal_evalcsJ‡‡‡fdd†‰t|tƒs@td|jjƒ‚nˆ|ƒS(u» Return a formatted dump of the tree in *node*. This is mainly useful for debugging purposes. The returned string will show the names and the values for fields. This makes the code impossible to evaluate, so if evaluation is wanted *annotate_fields* must be set to False. Attributes such as line numbers and column offsets are not dumped by default. If this is wanted, *include_attributes* can be set to True. cs tˆtƒrχfdd†tˆƒDƒ}dˆjjdjˆrYdd„|Dƒndd„|Dƒƒf}ˆrLjjrÇ||r‘dp”d7}|dj‡‡fd d†ˆjDƒƒ7}n|d Stˆtƒrd dj‡fd d†ˆDƒƒStˆƒS( Ncs(g|]\}}|ˆ|ƒf‘qS(((u.0uaub(u_format(u(/opt/alt/python33/lib64/python3.3/ast.pyu ds u)dump.._format..u%s(%su, css|]}d|VqdS(u%s=%sN((u.0ufield((u(/opt/alt/python33/lib64/python3.3/ast.pyu fsu(dump.._format..css|]\}}|VqdS(N((u.0uaub((u(/opt/alt/python33/lib64/python3.3/ast.pyu hsu c3s.|]$}d|ˆtˆ|ƒƒfVqdS(u%s=%sN(ugetattr(u.0ua(u_formatunode(u(/opt/alt/python33/lib64/python3.3/ast.pyu lsu)u[%s]c3s|]}ˆ|ƒVqdS(N((u.0ux(u_format(u(/opt/alt/python33/lib64/python3.3/ast.pyu ps( u isinstanceuASTu iter_fieldsu __class__u__name__ujoinu _attributesulisturepr(unodeufieldsurv(u_formatuannotate_fieldsuinclude_attributes(unodeu(/opt/alt/python33/lib64/python3.3/ast.pyu_formatbs$udump.._formatuexpected AST, got %r(u isinstanceuASTu TypeErroru __class__u__name__(unodeuannotate_fieldsuinclude_attributes((u_formatuannotate_fieldsuinclude_attributesu(/opt/alt/python33/lib64/python3.3/ast.pyudumpYs udumpc Cs^xWdD]O}||jkr||jkrt||ƒrt||t||ƒƒqqW|S(u‹ Copy source location (`lineno` and `col_offset` attributes) from *old_node* to *new_node* if possible, and return *new_node*. ulinenou col_offset(ulinenou col_offset(u _attributesuhasattrusetattrugetattr(unew_nodeuold_nodeuattr((u(/opt/alt/python33/lib64/python3.3/ast.pyu copy_locationws   u copy_locationcs&‡fdd†‰ˆ|ddƒ|S(u{ When you compile a node tree with compile(), the compiler expects lineno and col_offset attributes for every node that supports them. This is rather tedious to fill in for generated nodes, so this helper adds these attributes recursively where not already set, by setting them to the values of the parent node. It works recursively starting at *node*. cs—d|jkr6t|dƒs*||_q6|j}nd|jkrlt|dƒs`||_ql|j}nx$t|ƒD]}ˆ|||ƒqyWdS(Nulinenou col_offset(u _attributesuhasattrulinenou col_offsetuiter_child_nodes(unodeulinenou col_offsetuchild(u_fix(u(/opt/alt/python33/lib64/python3.3/ast.pyu_fix‹s    u#fix_missing_locations.._fixii((unode((u_fixu(/opt/alt/python33/lib64/python3.3/ast.pyufix_missing_locationsƒs ufix_missing_locationsicCsFx?t|ƒD]1}d|jkr t|ddƒ||_q q W|S(uœ Increment the line number of each node in the tree starting at *node* by *n*. This is useful to "move code" to a different location in a file. ulinenoi(uwalku _attributesugetattrulineno(unodeunuchild((u(/opt/alt/python33/lib64/python3.3/ast.pyuincrement_linenoœs uincrement_linenoc csEx>|jD]3}y|t||ƒfVWq tk r<Yq Xq WdS(us Yield a tuple of ``(fieldname, value)`` for each field in ``node._fields`` that is present on *node*. N(u_fieldsugetattruAttributeError(unodeufield((u(/opt/alt/python33/lib64/python3.3/ast.pyu iter_fields§s  u iter_fieldsccsrxkt|ƒD]]\}}t|tƒr0|Vq t|tƒr x(|D]}t|tƒrF|VqFqFWq q WdS(u‰ Yield all direct child nodes of *node*, that is, all fields that are nodes and all items of fields that are lists of nodes. N(u iter_fieldsu isinstanceuASTulist(unodeunameufielduitem((u(/opt/alt/python33/lib64/python3.3/ast.pyuiter_child_nodes³s uiter_child_nodescCsªt|tttfƒs1td|jjƒ‚n|jr¦t|jdtƒr¦t|jdj t ƒr¦|r•ddl }|j |jdj j ƒS|jdj j SdS(uª Return the docstring for the given node or None if no docstring can be found. If the node provided does not have docstrings a TypeError will be raised. u%r can't have docstringsiN(u isinstanceu FunctionDefuClassDefuModuleu TypeErroru __class__u__name__ubodyuExpruvalueuStruinspectucleandocus(unodeucleanuinspect((u(/opt/alt/python33/lib64/python3.3/ast.pyu get_docstringÁs u get_docstringccsTddlm}||gƒ}x.|rO|jƒ}|jt|ƒƒ|Vq"WdS(uå Recursively yield all descendant nodes in the tree starting at *node* (including *node* itself), in no specified order. This is useful if you only want to modify nodes in place and don't care about the context. i(udequeN(u collectionsudequeupopleftuextenduiter_child_nodes(unodeudequeutodo((u(/opt/alt/python33/lib64/python3.3/ast.pyuwalkÑs   uwalkcBs2|EeZdZdZdd„Zdd„ZdS(u NodeVisitoru< A node visitor base class that walks the abstract syntax tree and calls a visitor function for every node found. This function may return a value which is forwarded by the `visit` method. This class is meant to be subclassed, with the subclass adding visitor methods. Per default the visitor functions for the nodes are ``'visit_'`` + class name of the node. So a `TryFinally` node visit function would be `visit_TryFinally`. This behavior can be changed by overriding the `visit` method. If no visitor function exists for a node (return value `None`) the `generic_visit` visitor is used instead. Don't use the `NodeVisitor` if you want to apply changes to nodes during traversing. For this a special visitor exists (`NodeTransformer`) that allows modifications. cCs/d|jj}t|||jƒ}||ƒS(u Visit a node.uvisit_(u __class__u__name__ugetattru generic_visit(uselfunodeumethoduvisitor((u(/opt/alt/python33/lib64/python3.3/ast.pyuvisitósuNodeVisitor.visitcCs‚x{t|ƒD]m\}}t|tƒr[xO|D]%}t|tƒr/|j|ƒq/q/Wq t|tƒr |j|ƒq q WdS(u9Called if no explicit visitor function exists for a node.N(u iter_fieldsu isinstanceulistuASTuvisit(uselfunodeufielduvalueuitem((u(/opt/alt/python33/lib64/python3.3/ast.pyu generic_visitùs uNodeVisitor.generic_visitN(u__name__u __module__u __qualname__u__doc__uvisitu generic_visit(u __locals__((u(/opt/alt/python33/lib64/python3.3/ast.pyu NodeVisitorßs u NodeVisitorcBs&|EeZdZdZdd„ZdS(uNodeTransformeru\ A :class:`NodeVisitor` subclass that walks the abstract syntax tree and allows modification of nodes. The `NodeTransformer` will walk the AST and use the return value of the visitor methods to replace or remove the old node. If the return value of the visitor method is ``None``, the node will be removed from its location, otherwise it is replaced with the return value. The return value may be the original node in which case no replacement takes place. Here is an example transformer that rewrites all occurrences of name lookups (``foo``) to ``data['foo']``:: class RewriteName(NodeTransformer): def visit_Name(self, node): return copy_location(Subscript( value=Name(id='data', ctx=Load()), slice=Index(value=Str(s=node.id)), ctx=node.ctx ), node) Keep in mind that if the node you're operating on has child nodes you must either transform the child nodes yourself or call the :meth:`generic_visit` method for the node first. For nodes that were part of a collection of statements (that applies to all statement nodes), the visitor may also return a list of nodes rather than just a single node. Usually you use the transformer like this:: node = YourTransformer().visit(node) cCsxt|ƒD]\}}t||dƒ}t|tƒrÆg}xp|D]h}t|tƒr¢|j|ƒ}|dkr}qGq¢t|tƒs¢|j|ƒqGq¢n|j|ƒqGW||dd…s  3   %