diff options
| -rw-r--r-- | Doc/library/ast.rst | 13 | ||||
| -rw-r--r-- | Doc/whatsnew/3.9.rst | 8 | ||||
| -rw-r--r-- | Lib/ast.py | 45 | ||||
| -rw-r--r-- | Lib/test/test_ast.py | 62 | ||||
| -rw-r--r-- | Misc/NEWS.d/next/Library/2019-08-31-13-36-09.bpo-37995.rS8HzT.rst | 2 |
5 files changed, 118 insertions, 12 deletions
diff --git a/Doc/library/ast.rst b/Doc/library/ast.rst index 92bf891..cb8e7ec 100644 --- a/Doc/library/ast.rst +++ b/Doc/library/ast.rst @@ -319,7 +319,7 @@ and classes for traversing abstract syntax trees: node = YourTransformer().visit(node) -.. function:: dump(node, annotate_fields=True, include_attributes=False) +.. function:: dump(node, annotate_fields=True, include_attributes=False, *, indent=None) Return a formatted dump of the tree in *node*. This is mainly useful for debugging purposes. If *annotate_fields* is true (by default), @@ -329,6 +329,17 @@ and classes for traversing abstract syntax trees: numbers and column offsets are not dumped by default. If this is wanted, *include_attributes* can be set to true. + If *indent* is a non-negative integer or string, then the tree will be + pretty-printed with that indent level. An indent level + of 0, negative, or ``""`` will only insert newlines. ``None`` (the default) + selects the single line representation. Using a positive integer indent + indents that many spaces per level. If *indent* is a string (such as ``"\t"``), + that string is used to indent each level. + + .. versionchanged:: 3.9 + Added the *indent* option. + + .. seealso:: `Green Tree Snakes <https://greentreesnakes.readthedocs.io/>`_, an external documentation resource, has good diff --git a/Doc/whatsnew/3.9.rst b/Doc/whatsnew/3.9.rst index 5670cb5..deaefc7 100644 --- a/Doc/whatsnew/3.9.rst +++ b/Doc/whatsnew/3.9.rst @@ -109,6 +109,14 @@ New Modules Improved Modules ================ +ast +--- + +Added the *indent* option to :func:`~ast.dump` which allows it to produce a +multiline indented output. +(Contributed by Serhiy Storchaka in :issue:`37995`.) + + threading --------- @@ -96,7 +96,7 @@ def literal_eval(node_or_string): return _convert(node_or_string) -def dump(node, annotate_fields=True, include_attributes=False): +def dump(node, annotate_fields=True, include_attributes=False, *, indent=None): """ Return a formatted dump of the tree in node. This is mainly useful for debugging purposes. If annotate_fields is true (by default), @@ -104,11 +104,21 @@ def dump(node, annotate_fields=True, include_attributes=False): If annotate_fields is false, the result string will be more compact by omitting unambiguous field names. Attributes such as line numbers and column offsets are not dumped by default. If this is wanted, - include_attributes can be set to true. + include_attributes can be set to true. If indent is a non-negative + integer or string, then the tree will be pretty-printed with that indent + level. None (the default) selects the single line representation. """ - def _format(node): + def _format(node, level=0): + if indent is not None: + level += 1 + prefix = '\n' + indent * level + sep = ',\n' + indent * level + else: + prefix = '' + sep = ', ' if isinstance(node, AST): args = [] + allsimple = True keywords = annotate_fields for field in node._fields: try: @@ -116,23 +126,36 @@ def dump(node, annotate_fields=True, include_attributes=False): except AttributeError: keywords = True else: + value, simple = _format(value, level) + allsimple = allsimple and simple if keywords: - args.append('%s=%s' % (field, _format(value))) + args.append('%s=%s' % (field, value)) else: - args.append(_format(value)) + args.append(value) if include_attributes and node._attributes: - for a in node._attributes: + for attr in node._attributes: try: - args.append('%s=%s' % (a, _format(getattr(node, a)))) + value = getattr(node, attr) except AttributeError: pass - return '%s(%s)' % (node.__class__.__name__, ', '.join(args)) + else: + value, simple = _format(value, level) + allsimple = allsimple and simple + args.append('%s=%s' % (attr, value)) + if allsimple and len(args) <= 3: + return '%s(%s)' % (node.__class__.__name__, ', '.join(args)), not args + return '%s(%s%s)' % (node.__class__.__name__, prefix, sep.join(args)), False elif isinstance(node, list): - return '[%s]' % ', '.join(_format(x) for x in node) - return repr(node) + if not node: + return '[]', True + return '[%s%s]' % (prefix, sep.join(_format(x, level)[0] for x in node)), False + return repr(node), True + if not isinstance(node, AST): raise TypeError('expected AST, got %r' % node.__class__.__name__) - return _format(node) + if indent is not None and not isinstance(indent, str): + indent = ' ' * indent + return _format(node)[0] def copy_location(new_node, old_node): diff --git a/Lib/test/test_ast.py b/Lib/test/test_ast.py index 07bbb4c..47e259e 100644 --- a/Lib/test/test_ast.py +++ b/Lib/test/test_ast.py @@ -645,6 +645,68 @@ class ASTHelpers_Test(unittest.TestCase): "lineno=1, col_offset=0, end_lineno=1, end_col_offset=24)], type_ignores=[])" ) + def test_dump_indent(self): + node = ast.parse('spam(eggs, "and cheese")') + self.assertEqual(ast.dump(node, indent=3), """\ +Module( + body=[ + Expr( + value=Call( + func=Name(id='spam', ctx=Load()), + args=[ + Name(id='eggs', ctx=Load()), + Constant(value='and cheese', kind=None)], + keywords=[]))], + type_ignores=[])""") + self.assertEqual(ast.dump(node, annotate_fields=False, indent='\t'), """\ +Module( +\t[ +\t\tExpr( +\t\t\tCall( +\t\t\t\tName('spam', Load()), +\t\t\t\t[ +\t\t\t\t\tName('eggs', Load()), +\t\t\t\t\tConstant('and cheese', None)], +\t\t\t\t[]))], +\t[])""") + self.assertEqual(ast.dump(node, include_attributes=True, indent=3), """\ +Module( + body=[ + Expr( + value=Call( + func=Name( + id='spam', + ctx=Load(), + lineno=1, + col_offset=0, + end_lineno=1, + end_col_offset=4), + args=[ + Name( + id='eggs', + ctx=Load(), + lineno=1, + col_offset=5, + end_lineno=1, + end_col_offset=9), + Constant( + value='and cheese', + kind=None, + lineno=1, + col_offset=11, + end_lineno=1, + end_col_offset=23)], + keywords=[], + lineno=1, + col_offset=0, + end_lineno=1, + end_col_offset=24), + lineno=1, + col_offset=0, + end_lineno=1, + end_col_offset=24)], + type_ignores=[])""") + def test_dump_incomplete(self): node = ast.Raise(lineno=3, col_offset=4) self.assertEqual(ast.dump(node), diff --git a/Misc/NEWS.d/next/Library/2019-08-31-13-36-09.bpo-37995.rS8HzT.rst b/Misc/NEWS.d/next/Library/2019-08-31-13-36-09.bpo-37995.rS8HzT.rst new file mode 100644 index 0000000..19482b6 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2019-08-31-13-36-09.bpo-37995.rS8HzT.rst @@ -0,0 +1,2 @@ +Added the *indent* option to :func:`ast.dump` which allows it to produce a +multiline indented output. |