| 1 | # -*- coding: utf-8 -*- |
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| 2 | # |
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| 3 | # Copyright (C) 2008-2010 Edgewall Software |
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| 4 | # All rights reserved. |
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| 5 | # |
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| 6 | # This software is licensed as described in the file COPYING, which |
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| 7 | # you should have received as part of this distribution. The terms |
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| 8 | # are also available at http://genshi.edgewall.org/wiki/License. |
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| 9 | # |
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| 10 | # This software consists of voluntary contributions made by many |
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| 11 | # individuals. For the exact contribution history, see the revision |
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| 12 | # history and logs, available at http://genshi.edgewall.org/log/. |
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| 13 | |
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| 14 | """Support classes for generating code from abstract syntax trees.""" |
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| 15 | |
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| 16 | try: |
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| 17 | import _ast |
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| 18 | except ImportError: |
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| 19 | from genshi.template.ast24 import _ast, parse |
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| 20 | else: |
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| 21 | def parse(source, mode): |
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| 22 | return compile(source, '', mode, _ast.PyCF_ONLY_AST) |
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| 23 | |
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| 24 | |
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| 25 | __docformat__ = 'restructuredtext en' |
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| 26 | |
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| 27 | |
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| 28 | class ASTCodeGenerator(object): |
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| 29 | """General purpose base class for AST transformations. |
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| 30 | |
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| 31 | Every visitor method can be overridden to return an AST node that has been |
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| 32 | altered or replaced in some way. |
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| 33 | """ |
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| 34 | def __init__(self, tree): |
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| 35 | self.lines_info = [] |
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| 36 | self.line_info = None |
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| 37 | self.code = '' |
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| 38 | self.line = None |
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| 39 | self.last = None |
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| 40 | self.indent = 0 |
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| 41 | self.blame_stack = [] |
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| 42 | self.visit(tree) |
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| 43 | if self.line.strip(): |
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| 44 | self.code += self.line + '\n' |
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| 45 | self.lines_info.append(self.line_info) |
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| 46 | self.line = None |
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| 47 | self.line_info = None |
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| 48 | |
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| 49 | def _change_indent(self, delta): |
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| 50 | self.indent += delta |
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| 51 | |
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| 52 | def _new_line(self): |
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| 53 | if self.line is not None: |
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| 54 | self.code += self.line + '\n' |
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| 55 | self.lines_info.append(self.line_info) |
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| 56 | self.line = ' '*4*self.indent |
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| 57 | if len(self.blame_stack) == 0: |
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| 58 | self.line_info = [] |
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| 59 | self.last = None |
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| 60 | else: |
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| 61 | self.line_info = [(0, self.blame_stack[-1],)] |
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| 62 | self.last = self.blame_stack[-1] |
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| 63 | |
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| 64 | def _write(self, s): |
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| 65 | if len(s) == 0: |
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| 66 | return |
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| 67 | if len(self.blame_stack) == 0: |
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| 68 | if self.last is not None: |
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| 69 | self.last = None |
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| 70 | self.line_info.append((len(self.line), self.last)) |
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| 71 | else: |
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| 72 | if self.last != self.blame_stack[-1]: |
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| 73 | self.last = self.blame_stack[-1] |
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| 74 | self.line_info.append((len(self.line), self.last)) |
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| 75 | self.line += s |
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| 76 | |
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| 77 | def visit(self, node): |
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| 78 | if node is None: |
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| 79 | return None |
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| 80 | if type(node) is tuple: |
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| 81 | return tuple([self.visit(n) for n in node]) |
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| 82 | try: |
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| 83 | self.blame_stack.append((node.lineno, node.col_offset,)) |
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| 84 | info = True |
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| 85 | except AttributeError: |
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| 86 | info = False |
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| 87 | visitor = getattr(self, 'visit_%s' % node.__class__.__name__, None) |
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| 88 | if visitor is None: |
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| 89 | raise Exception('Unhandled node type %r' % type(node)) |
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| 90 | ret = visitor(node) |
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| 91 | if info: |
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| 92 | self.blame_stack.pop() |
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| 93 | return ret |
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| 94 | |
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| 95 | def visit_Module(self, node): |
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| 96 | for n in node.body: |
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| 97 | self.visit(n) |
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| 98 | visit_Interactive = visit_Module |
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| 99 | visit_Suite = visit_Module |
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| 100 | |
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| 101 | def visit_Expression(self, node): |
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| 102 | self._new_line() |
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| 103 | return self.visit(node.body) |
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| 104 | |
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| 105 | # arguments = (expr* args, identifier? vararg, |
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| 106 | # identifier? kwarg, expr* defaults) |
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| 107 | def visit_arguments(self, node): |
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| 108 | first = True |
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| 109 | no_default_count = len(node.args) - len(node.defaults) |
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| 110 | for i, arg in enumerate(node.args): |
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| 111 | if not first: |
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| 112 | self._write(', ') |
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| 113 | else: |
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| 114 | first = False |
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| 115 | self.visit(arg) |
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| 116 | if i >= no_default_count: |
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| 117 | self._write('=') |
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| 118 | self.visit(node.defaults[i - no_default_count]) |
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| 119 | if getattr(node, 'vararg', None): |
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| 120 | if not first: |
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| 121 | self._write(', ') |
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| 122 | else: |
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| 123 | first = False |
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| 124 | self._write('*' + node.vararg) |
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| 125 | if getattr(node, 'kwarg', None): |
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| 126 | if not first: |
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| 127 | self._write(', ') |
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| 128 | else: |
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| 129 | first = False |
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| 130 | self._write('**' + node.kwarg) |
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| 131 | |
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| 132 | # FunctionDef(identifier name, arguments args, |
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| 133 | # stmt* body, expr* decorator_list) |
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| 134 | def visit_FunctionDef(self, node): |
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| 135 | decarators = () |
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| 136 | if hasattr(node, 'decorator_list'): |
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| 137 | decorators = getattr(node, 'decorator_list') |
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| 138 | else: # different name in earlier Python versions |
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| 139 | decorators = getattr(node, 'decorators', ()) |
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| 140 | for decorator in decorators: |
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| 141 | self._new_line() |
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| 142 | self._write('@') |
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| 143 | self.visit(decorator) |
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| 144 | self._new_line() |
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| 145 | self._write('def ' + node.name + '(') |
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| 146 | self.visit(node.args) |
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| 147 | self._write('):') |
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| 148 | self._change_indent(1) |
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| 149 | for statement in node.body: |
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| 150 | self.visit(statement) |
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| 151 | self._change_indent(-1) |
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| 152 | |
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| 153 | # ClassDef(identifier name, expr* bases, stmt* body) |
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| 154 | def visit_ClassDef(self, node): |
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| 155 | self._new_line() |
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| 156 | self._write('class ' + node.name) |
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| 157 | if node.bases: |
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| 158 | self._write('(') |
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| 159 | self.visit(node.bases[0]) |
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| 160 | for base in node.bases[1:]: |
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| 161 | self._write(', ') |
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| 162 | self.visit(base) |
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| 163 | self._write(')') |
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| 164 | self._write(':') |
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| 165 | self._change_indent(1) |
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| 166 | for statement in node.body: |
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| 167 | self.visit(statement) |
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| 168 | self._change_indent(-1) |
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| 169 | |
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| 170 | # Return(expr? value) |
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| 171 | def visit_Return(self, node): |
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| 172 | self._new_line() |
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| 173 | self._write('return') |
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| 174 | if getattr(node, 'value', None): |
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| 175 | self._write(' ') |
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| 176 | self.visit(node.value) |
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| 177 | |
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| 178 | # Delete(expr* targets) |
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| 179 | def visit_Delete(self, node): |
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| 180 | self._new_line() |
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| 181 | self._write('del ') |
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| 182 | self.visit(node.targets[0]) |
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| 183 | for target in node.targets[1:]: |
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| 184 | self._write(', ') |
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| 185 | self.visit(target) |
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| 186 | |
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| 187 | # Assign(expr* targets, expr value) |
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| 188 | def visit_Assign(self, node): |
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| 189 | self._new_line() |
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| 190 | for target in node.targets: |
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| 191 | self.visit(target) |
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| 192 | self._write(' = ') |
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| 193 | self.visit(node.value) |
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| 194 | |
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| 195 | # AugAssign(expr target, operator op, expr value) |
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| 196 | def visit_AugAssign(self, node): |
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| 197 | self._new_line() |
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| 198 | self.visit(node.target) |
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| 199 | self._write(' ' + self.binary_operators[node.op.__class__] + '= ') |
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| 200 | self.visit(node.value) |
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| 201 | |
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| 202 | # Print(expr? dest, expr* values, bool nl) |
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| 203 | def visit_Print(self, node): |
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| 204 | self._new_line() |
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| 205 | self._write('print') |
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| 206 | if getattr(node, 'dest', None): |
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| 207 | self._write(' >> ') |
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| 208 | self.visit(node.dest) |
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| 209 | if getattr(node, 'values', None): |
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| 210 | self._write(', ') |
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| 211 | else: |
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| 212 | self._write(' ') |
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| 213 | if getattr(node, 'values', None): |
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| 214 | self.visit(node.values[0]) |
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| 215 | for value in node.values[1:]: |
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| 216 | self._write(', ') |
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| 217 | self.visit(value) |
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| 218 | if not node.nl: |
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| 219 | self._write(',') |
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| 220 | |
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| 221 | # For(expr target, expr iter, stmt* body, stmt* orelse) |
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| 222 | def visit_For(self, node): |
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| 223 | self._new_line() |
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| 224 | self._write('for ') |
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| 225 | self.visit(node.target) |
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| 226 | self._write(' in ') |
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| 227 | self.visit(node.iter) |
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| 228 | self._write(':') |
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| 229 | self._change_indent(1) |
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| 230 | for statement in node.body: |
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| 231 | self.visit(statement) |
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| 232 | self._change_indent(-1) |
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| 233 | if getattr(node, 'orelse', None): |
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| 234 | self._new_line() |
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| 235 | self._write('else:') |
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| 236 | self._change_indent(1) |
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| 237 | for statement in node.orelse: |
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| 238 | self.visit(statement) |
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| 239 | self._change_indent(-1) |
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| 240 | |
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| 241 | # While(expr test, stmt* body, stmt* orelse) |
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| 242 | def visit_While(self, node): |
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| 243 | self._new_line() |
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| 244 | self._write('while ') |
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| 245 | self.visit(node.test) |
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| 246 | self._write(':') |
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| 247 | self._change_indent(1) |
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| 248 | for statement in node.body: |
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| 249 | self.visit(statement) |
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| 250 | self._change_indent(-1) |
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| 251 | if getattr(node, 'orelse', None): |
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| 252 | self._new_line() |
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| 253 | self._write('else:') |
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| 254 | self._change_indent(1) |
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| 255 | for statement in node.orelse: |
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| 256 | self.visit(statement) |
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| 257 | self._change_indent(-1) |
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| 258 | |
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| 259 | # If(expr test, stmt* body, stmt* orelse) |
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| 260 | def visit_If(self, node): |
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| 261 | self._new_line() |
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| 262 | self._write('if ') |
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| 263 | self.visit(node.test) |
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| 264 | self._write(':') |
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| 265 | self._change_indent(1) |
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| 266 | for statement in node.body: |
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| 267 | self.visit(statement) |
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| 268 | self._change_indent(-1) |
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| 269 | if getattr(node, 'orelse', None): |
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| 270 | self._new_line() |
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| 271 | self._write('else:') |
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| 272 | self._change_indent(1) |
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| 273 | for statement in node.orelse: |
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| 274 | self.visit(statement) |
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| 275 | self._change_indent(-1) |
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| 276 | |
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| 277 | # With(expr context_expr, expr? optional_vars, stmt* body) |
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| 278 | def visit_With(self, node): |
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| 279 | self._new_line() |
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| 280 | self._write('with ') |
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| 281 | self.visit(node.context_expr) |
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| 282 | if getattr(node, 'optional_vars', None): |
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| 283 | self._write(' as ') |
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| 284 | self.visit(node.optional_vars) |
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| 285 | self._write(':') |
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| 286 | self._change_indent(1) |
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| 287 | for statement in node.body: |
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| 288 | self.visit(statement) |
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| 289 | self._change_indent(-1) |
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| 290 | |
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| 291 | |
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| 292 | # Raise(expr? type, expr? inst, expr? tback) |
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| 293 | def visit_Raise(self, node): |
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| 294 | self._new_line() |
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| 295 | self._write('raise') |
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| 296 | if not node.type: |
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| 297 | return |
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| 298 | self._write(' ') |
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| 299 | self.visit(node.type) |
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| 300 | if not node.inst: |
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| 301 | return |
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| 302 | self._write(', ') |
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| 303 | self.visit(node.inst) |
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| 304 | if not node.tback: |
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| 305 | return |
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| 306 | self._write(', ') |
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| 307 | self.visit(node.tback) |
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| 308 | |
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| 309 | # TryExcept(stmt* body, excepthandler* handlers, stmt* orelse) |
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| 310 | def visit_TryExcept(self, node): |
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| 311 | self._new_line() |
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| 312 | self._write('try:') |
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| 313 | self._change_indent(1) |
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| 314 | for statement in node.body: |
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| 315 | self.visit(statement) |
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| 316 | self._change_indent(-1) |
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| 317 | if getattr(node, 'handlers', None): |
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| 318 | for handler in node.handlers: |
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| 319 | self.visit(handler) |
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| 320 | self._new_line() |
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| 321 | if getattr(node, 'orelse', None): |
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| 322 | self._write('else:') |
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| 323 | self._change_indent(1) |
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| 324 | for statement in node.orelse: |
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| 325 | self.visit(statement) |
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| 326 | self._change_indent(-1) |
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| 327 | |
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| 328 | # excepthandler = (expr? type, expr? name, stmt* body) |
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| 329 | def visit_ExceptHandler(self, node): |
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| 330 | self._new_line() |
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| 331 | self._write('except') |
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| 332 | if getattr(node, 'type', None): |
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| 333 | self._write(' ') |
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| 334 | self.visit(node.type) |
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| 335 | if getattr(node, 'name', None): |
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| 336 | self._write(', ') |
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| 337 | self.visit(node.name) |
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| 338 | self._write(':') |
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| 339 | self._change_indent(1) |
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| 340 | for statement in node.body: |
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| 341 | self.visit(statement) |
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| 342 | self._change_indent(-1) |
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| 343 | visit_excepthandler = visit_ExceptHandler |
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| 344 | |
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| 345 | # TryFinally(stmt* body, stmt* finalbody) |
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| 346 | def visit_TryFinally(self, node): |
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| 347 | self._new_line() |
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| 348 | self._write('try:') |
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| 349 | self._change_indent(1) |
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| 350 | for statement in node.body: |
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| 351 | self.visit(statement) |
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| 352 | self._change_indent(-1) |
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| 353 | |
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| 354 | if getattr(node, 'finalbody', None): |
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| 355 | self._new_line() |
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| 356 | self._write('finally:') |
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| 357 | self._change_indent(1) |
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| 358 | for statement in node.finalbody: |
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| 359 | self.visit(statement) |
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| 360 | self._change_indent(-1) |
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| 361 | |
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| 362 | # Assert(expr test, expr? msg) |
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| 363 | def visit_Assert(self, node): |
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| 364 | self._new_line() |
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| 365 | self._write('assert ') |
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| 366 | self.visit(node.test) |
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| 367 | if getattr(node, 'msg', None): |
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| 368 | self._write(', ') |
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| 369 | self.visit(node.msg) |
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| 370 | |
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| 371 | def visit_alias(self, node): |
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| 372 | self._write(node.name) |
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| 373 | if getattr(node, 'asname', None): |
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| 374 | self._write(' as ') |
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| 375 | self._write(node.asname) |
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| 376 | |
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| 377 | # Import(alias* names) |
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| 378 | def visit_Import(self, node): |
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| 379 | self._new_line() |
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| 380 | self._write('import ') |
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| 381 | self.visit(node.names[0]) |
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| 382 | for name in node.names[1:]: |
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| 383 | self._write(', ') |
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| 384 | self.visit(name) |
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| 385 | |
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| 386 | # ImportFrom(identifier module, alias* names, int? level) |
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| 387 | def visit_ImportFrom(self, node): |
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| 388 | self._new_line() |
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| 389 | self._write('from ') |
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| 390 | if node.level: |
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| 391 | self._write('.' * node.level) |
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| 392 | self._write(node.module) |
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| 393 | self._write(' import ') |
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| 394 | self.visit(node.names[0]) |
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| 395 | for name in node.names[1:]: |
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| 396 | self._write(', ') |
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| 397 | self.visit(name) |
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| 398 | |
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| 399 | # Exec(expr body, expr? globals, expr? locals) |
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| 400 | def visit_Exec(self, node): |
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| 401 | self._new_line() |
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| 402 | self._write('exec ') |
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| 403 | self.visit(node.body) |
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| 404 | if not node.globals: |
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| 405 | return |
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| 406 | self._write(', ') |
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| 407 | self.visit(node.globals) |
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| 408 | if not node.locals: |
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| 409 | return |
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| 410 | self._write(', ') |
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| 411 | self.visit(node.locals) |
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| 412 | |
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| 413 | # Global(identifier* names) |
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| 414 | def visit_Global(self, node): |
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| 415 | self._new_line() |
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| 416 | self._write('global ') |
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| 417 | self.visit(node.names[0]) |
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| 418 | for name in node.names[1:]: |
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| 419 | self._write(', ') |
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| 420 | self.visit(name) |
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| 421 | |
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| 422 | # Expr(expr value) |
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| 423 | def visit_Expr(self, node): |
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| 424 | self._new_line() |
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| 425 | self.visit(node.value) |
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| 426 | |
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| 427 | # Pass |
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| 428 | def visit_Pass(self, node): |
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| 429 | self._new_line() |
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| 430 | self._write('pass') |
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| 431 | |
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| 432 | # Break |
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| 433 | def visit_Break(self, node): |
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| 434 | self._new_line() |
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| 435 | self._write('break') |
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| 436 | |
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| 437 | # Continue |
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| 438 | def visit_Continue(self, node): |
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| 439 | self._new_line() |
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| 440 | self._write('continue') |
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| 441 | |
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| 442 | ### EXPRESSIONS |
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| 443 | def with_parens(f): |
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| 444 | def _f(self, node): |
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| 445 | self._write('(') |
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| 446 | f(self, node) |
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| 447 | self._write(')') |
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| 448 | return _f |
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| 449 | |
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| 450 | bool_operators = {_ast.And: 'and', _ast.Or: 'or'} |
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| 451 | |
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| 452 | # BoolOp(boolop op, expr* values) |
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| 453 | @with_parens |
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| 454 | def visit_BoolOp(self, node): |
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| 455 | joiner = ' ' + self.bool_operators[node.op.__class__] + ' ' |
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| 456 | self.visit(node.values[0]) |
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| 457 | for value in node.values[1:]: |
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| 458 | self._write(joiner) |
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| 459 | self.visit(value) |
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| 460 | |
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| 461 | binary_operators = { |
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| 462 | _ast.Add: '+', |
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| 463 | _ast.Sub: '-', |
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| 464 | _ast.Mult: '*', |
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| 465 | _ast.Div: '/', |
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| 466 | _ast.Mod: '%', |
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| 467 | _ast.Pow: '**', |
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| 468 | _ast.LShift: '<<', |
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| 469 | _ast.RShift: '>>', |
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| 470 | _ast.BitOr: '|', |
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| 471 | _ast.BitXor: '^', |
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| 472 | _ast.BitAnd: '&', |
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| 473 | _ast.FloorDiv: '//' |
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| 474 | } |
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| 475 | |
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| 476 | # BinOp(expr left, operator op, expr right) |
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| 477 | @with_parens |
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| 478 | def visit_BinOp(self, node): |
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| 479 | self.visit(node.left) |
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| 480 | self._write(' ' + self.binary_operators[node.op.__class__] + ' ') |
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| 481 | self.visit(node.right) |
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| 482 | |
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| 483 | unary_operators = { |
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| 484 | _ast.Invert: '~', |
|---|
| 485 | _ast.Not: 'not', |
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| 486 | _ast.UAdd: '+', |
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| 487 | _ast.USub: '-', |
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| 488 | } |
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| 489 | |
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| 490 | # UnaryOp(unaryop op, expr operand) |
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| 491 | def visit_UnaryOp(self, node): |
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| 492 | self._write(self.unary_operators[node.op.__class__] + ' ') |
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| 493 | self.visit(node.operand) |
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| 494 | |
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| 495 | # Lambda(arguments args, expr body) |
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| 496 | @with_parens |
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| 497 | def visit_Lambda(self, node): |
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| 498 | self._write('lambda ') |
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| 499 | self.visit(node.args) |
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| 500 | self._write(': ') |
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| 501 | self.visit(node.body) |
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| 502 | |
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| 503 | # IfExp(expr test, expr body, expr orelse) |
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| 504 | @with_parens |
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| 505 | def visit_IfExp(self, node): |
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| 506 | self.visit(node.body) |
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| 507 | self._write(' if ') |
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| 508 | self.visit(node.test) |
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| 509 | self._write(' else ') |
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| 510 | self.visit(node.orelse) |
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| 511 | |
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| 512 | # Dict(expr* keys, expr* values) |
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| 513 | def visit_Dict(self, node): |
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| 514 | self._write('{') |
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| 515 | for key, value in zip(node.keys, node.values): |
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| 516 | self.visit(key) |
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| 517 | self._write(': ') |
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| 518 | self.visit(value) |
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| 519 | self._write(', ') |
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| 520 | self._write('}') |
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| 521 | |
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| 522 | # ListComp(expr elt, comprehension* generators) |
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| 523 | def visit_ListComp(self, node): |
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| 524 | self._write('[') |
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| 525 | self.visit(node.elt) |
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| 526 | for generator in node.generators: |
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| 527 | # comprehension = (expr target, expr iter, expr* ifs) |
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| 528 | self._write(' for ') |
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| 529 | self.visit(generator.target) |
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| 530 | self._write(' in ') |
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| 531 | self.visit(generator.iter) |
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| 532 | for ifexpr in generator.ifs: |
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| 533 | self._write(' if ') |
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| 534 | self.visit(ifexpr) |
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| 535 | self._write(']') |
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| 536 | |
|---|
| 537 | # GeneratorExp(expr elt, comprehension* generators) |
|---|
| 538 | def visit_GeneratorExp(self, node): |
|---|
| 539 | self._write('(') |
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| 540 | self.visit(node.elt) |
|---|
| 541 | for generator in node.generators: |
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| 542 | # comprehension = (expr target, expr iter, expr* ifs) |
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| 543 | self._write(' for ') |
|---|
| 544 | self.visit(generator.target) |
|---|
| 545 | self._write(' in ') |
|---|
| 546 | self.visit(generator.iter) |
|---|
| 547 | for ifexpr in generator.ifs: |
|---|
| 548 | self._write(' if ') |
|---|
| 549 | self.visit(ifexpr) |
|---|
| 550 | self._write(')') |
|---|
| 551 | |
|---|
| 552 | # Yield(expr? value) |
|---|
| 553 | def visit_Yield(self, node): |
|---|
| 554 | self._write('yield') |
|---|
| 555 | if getattr(node, 'value', None): |
|---|
| 556 | self._write(' ') |
|---|
| 557 | self.visit(node.value) |
|---|
| 558 | |
|---|
| 559 | comparision_operators = { |
|---|
| 560 | _ast.Eq: '==', |
|---|
| 561 | _ast.NotEq: '!=', |
|---|
| 562 | _ast.Lt: '<', |
|---|
| 563 | _ast.LtE: '<=', |
|---|
| 564 | _ast.Gt: '>', |
|---|
| 565 | _ast.GtE: '>=', |
|---|
| 566 | _ast.Is: 'is', |
|---|
| 567 | _ast.IsNot: 'is not', |
|---|
| 568 | _ast.In: 'in', |
|---|
| 569 | _ast.NotIn: 'not in', |
|---|
| 570 | } |
|---|
| 571 | |
|---|
| 572 | # Compare(expr left, cmpop* ops, expr* comparators) |
|---|
| 573 | @with_parens |
|---|
| 574 | def visit_Compare(self, node): |
|---|
| 575 | self.visit(node.left) |
|---|
| 576 | for op, comparator in zip(node.ops, node.comparators): |
|---|
| 577 | self._write(' ' + self.comparision_operators[op.__class__] + ' ') |
|---|
| 578 | self.visit(comparator) |
|---|
| 579 | |
|---|
| 580 | # Call(expr func, expr* args, keyword* keywords, |
|---|
| 581 | # expr? starargs, expr? kwargs) |
|---|
| 582 | def visit_Call(self, node): |
|---|
| 583 | self.visit(node.func) |
|---|
| 584 | self._write('(') |
|---|
| 585 | first = True |
|---|
| 586 | for arg in node.args: |
|---|
| 587 | if not first: |
|---|
| 588 | self._write(', ') |
|---|
| 589 | first = False |
|---|
| 590 | self.visit(arg) |
|---|
| 591 | |
|---|
| 592 | for keyword in node.keywords: |
|---|
| 593 | if not first: |
|---|
| 594 | self._write(', ') |
|---|
| 595 | first = False |
|---|
| 596 | # keyword = (identifier arg, expr value) |
|---|
| 597 | self._write(keyword.arg) |
|---|
| 598 | self._write('=') |
|---|
| 599 | self.visit(keyword.value) |
|---|
| 600 | if getattr(node, 'starargs', None): |
|---|
| 601 | if not first: |
|---|
| 602 | self._write(', ') |
|---|
| 603 | first = False |
|---|
| 604 | self._write('*') |
|---|
| 605 | self.visit(node.starargs) |
|---|
| 606 | |
|---|
| 607 | if getattr(node, 'kwargs', None): |
|---|
| 608 | if not first: |
|---|
| 609 | self._write(', ') |
|---|
| 610 | first = False |
|---|
| 611 | self._write('**') |
|---|
| 612 | self.visit(node.kwargs) |
|---|
| 613 | self._write(')') |
|---|
| 614 | |
|---|
| 615 | # Repr(expr value) |
|---|
| 616 | def visit_Repr(self, node): |
|---|
| 617 | self._write('`') |
|---|
| 618 | self.visit(node.value) |
|---|
| 619 | self._write('`') |
|---|
| 620 | |
|---|
| 621 | # Num(object n) |
|---|
| 622 | def visit_Num(self, node): |
|---|
| 623 | self._write(repr(node.n)) |
|---|
| 624 | |
|---|
| 625 | # Str(string s) |
|---|
| 626 | def visit_Str(self, node): |
|---|
| 627 | self._write(repr(node.s)) |
|---|
| 628 | |
|---|
| 629 | # Attribute(expr value, identifier attr, expr_context ctx) |
|---|
| 630 | def visit_Attribute(self, node): |
|---|
| 631 | self.visit(node.value) |
|---|
| 632 | self._write('.') |
|---|
| 633 | self._write(node.attr) |
|---|
| 634 | |
|---|
| 635 | # Subscript(expr value, slice slice, expr_context ctx) |
|---|
| 636 | def visit_Subscript(self, node): |
|---|
| 637 | self.visit(node.value) |
|---|
| 638 | self._write('[') |
|---|
| 639 | def _process_slice(node): |
|---|
| 640 | if isinstance(node, _ast.Ellipsis): |
|---|
| 641 | self._write('...') |
|---|
| 642 | elif isinstance(node, _ast.Slice): |
|---|
| 643 | if getattr(node, 'lower', 'None'): |
|---|
| 644 | self.visit(node.lower) |
|---|
| 645 | self._write(':') |
|---|
| 646 | if getattr(node, 'upper', None): |
|---|
| 647 | self.visit(node.upper) |
|---|
| 648 | if getattr(node, 'step', None): |
|---|
| 649 | self._write(':') |
|---|
| 650 | self.visit(node.step) |
|---|
| 651 | elif isinstance(node, _ast.Index): |
|---|
| 652 | self.visit(node.value) |
|---|
| 653 | elif isinstance(node, _ast.ExtSlice): |
|---|
| 654 | self.visit(node.dims[0]) |
|---|
| 655 | for dim in node.dims[1:]: |
|---|
| 656 | self._write(', ') |
|---|
| 657 | self.visit(dim) |
|---|
| 658 | else: |
|---|
| 659 | raise NotImplemented('Slice type not implemented') |
|---|
| 660 | _process_slice(node.slice) |
|---|
| 661 | self._write(']') |
|---|
| 662 | |
|---|
| 663 | # Name(identifier id, expr_context ctx) |
|---|
| 664 | def visit_Name(self, node): |
|---|
| 665 | self._write(node.id) |
|---|
| 666 | |
|---|
| 667 | # List(expr* elts, expr_context ctx) |
|---|
| 668 | def visit_List(self, node): |
|---|
| 669 | self._write('[') |
|---|
| 670 | for elt in node.elts: |
|---|
| 671 | self.visit(elt) |
|---|
| 672 | self._write(', ') |
|---|
| 673 | self._write(']') |
|---|
| 674 | |
|---|
| 675 | # Tuple(expr *elts, expr_context ctx) |
|---|
| 676 | def visit_Tuple(self, node): |
|---|
| 677 | self._write('(') |
|---|
| 678 | for elt in node.elts: |
|---|
| 679 | self.visit(elt) |
|---|
| 680 | self._write(', ') |
|---|
| 681 | self._write(')') |
|---|
| 682 | |
|---|
| 683 | |
|---|
| 684 | class ASTTransformer(object): |
|---|
| 685 | """General purpose base class for AST transformations. |
|---|
| 686 | |
|---|
| 687 | Every visitor method can be overridden to return an AST node that has been |
|---|
| 688 | altered or replaced in some way. |
|---|
| 689 | """ |
|---|
| 690 | |
|---|
| 691 | def visit(self, node): |
|---|
| 692 | if node is None: |
|---|
| 693 | return None |
|---|
| 694 | if type(node) is tuple: |
|---|
| 695 | return tuple([self.visit(n) for n in node]) |
|---|
| 696 | visitor = getattr(self, 'visit_%s' % node.__class__.__name__, None) |
|---|
| 697 | if visitor is None: |
|---|
| 698 | return node |
|---|
| 699 | return visitor(node) |
|---|
| 700 | |
|---|
| 701 | def _clone(self, node): |
|---|
| 702 | clone = node.__class__() |
|---|
| 703 | for name in getattr(clone, '_attributes', ()): |
|---|
| 704 | try: |
|---|
| 705 | setattr(clone, 'name', getattr(node, name)) |
|---|
| 706 | except AttributeError: |
|---|
| 707 | pass |
|---|
| 708 | for name in clone._fields: |
|---|
| 709 | try: |
|---|
| 710 | value = getattr(node, name) |
|---|
| 711 | except AttributeError: |
|---|
| 712 | pass |
|---|
| 713 | else: |
|---|
| 714 | if value is None: |
|---|
| 715 | pass |
|---|
| 716 | elif isinstance(value, list): |
|---|
| 717 | value = [self.visit(x) for x in value] |
|---|
| 718 | elif isinstance(value, tuple): |
|---|
| 719 | value = tuple(self.visit(x) for x in value) |
|---|
| 720 | else: |
|---|
| 721 | value = self.visit(value) |
|---|
| 722 | setattr(clone, name, value) |
|---|
| 723 | return clone |
|---|
| 724 | |
|---|
| 725 | visit_Module = _clone |
|---|
| 726 | visit_Interactive = _clone |
|---|
| 727 | visit_Expression = _clone |
|---|
| 728 | visit_Suite = _clone |
|---|
| 729 | |
|---|
| 730 | visit_FunctionDef = _clone |
|---|
| 731 | visit_ClassDef = _clone |
|---|
| 732 | visit_Return = _clone |
|---|
| 733 | visit_Delete = _clone |
|---|
| 734 | visit_Assign = _clone |
|---|
| 735 | visit_AugAssign = _clone |
|---|
| 736 | visit_Print = _clone |
|---|
| 737 | visit_For = _clone |
|---|
| 738 | visit_While = _clone |
|---|
| 739 | visit_If = _clone |
|---|
| 740 | visit_With = _clone |
|---|
| 741 | visit_Raise = _clone |
|---|
| 742 | visit_TryExcept = _clone |
|---|
| 743 | visit_TryFinally = _clone |
|---|
| 744 | visit_Assert = _clone |
|---|
| 745 | visit_ExceptHandler = _clone |
|---|
| 746 | |
|---|
| 747 | visit_Import = _clone |
|---|
| 748 | visit_ImportFrom = _clone |
|---|
| 749 | visit_Exec = _clone |
|---|
| 750 | visit_Global = _clone |
|---|
| 751 | visit_Expr = _clone |
|---|
| 752 | # Pass, Break, Continue don't need to be copied |
|---|
| 753 | |
|---|
| 754 | visit_BoolOp = _clone |
|---|
| 755 | visit_BinOp = _clone |
|---|
| 756 | visit_UnaryOp = _clone |
|---|
| 757 | visit_Lambda = _clone |
|---|
| 758 | visit_IfExp = _clone |
|---|
| 759 | visit_Dict = _clone |
|---|
| 760 | visit_ListComp = _clone |
|---|
| 761 | visit_GeneratorExp = _clone |
|---|
| 762 | visit_Yield = _clone |
|---|
| 763 | visit_Compare = _clone |
|---|
| 764 | visit_Call = _clone |
|---|
| 765 | visit_Repr = _clone |
|---|
| 766 | # Num, Str don't need to be copied |
|---|
| 767 | |
|---|
| 768 | visit_Attribute = _clone |
|---|
| 769 | visit_Subscript = _clone |
|---|
| 770 | visit_Name = _clone |
|---|
| 771 | visit_List = _clone |
|---|
| 772 | visit_Tuple = _clone |
|---|
| 773 | |
|---|
| 774 | visit_comprehension = _clone |
|---|
| 775 | visit_excepthandler = _clone |
|---|
| 776 | visit_arguments = _clone |
|---|
| 777 | visit_keyword = _clone |
|---|
| 778 | visit_alias = _clone |
|---|
| 779 | |
|---|
| 780 | visit_Slice = _clone |
|---|
| 781 | visit_ExtSlice = _clone |
|---|
| 782 | visit_Index = _clone |
|---|
| 783 | |
|---|
| 784 | del _clone |
|---|
