[Python-checkins] bpo-37995: Add an option to ast.dump() to produce a multiline output. (GH-15631)
Serhiy Storchaka
webhook-mailer at python.org
Mon Sep 9 12:33:16 EDT 2019
https://github.com/python/cpython/commit/850573b836d5b82d1a1ebe75a635aaa0a3dff997
commit: 850573b836d5b82d1a1ebe75a635aaa0a3dff997
branch: master
author: Serhiy Storchaka <storchaka at gmail.com>
committer: GitHub <noreply at github.com>
date: 2019-09-09T19:33:13+03:00
summary:
bpo-37995: Add an option to ast.dump() to produce a multiline output. (GH-15631)
files:
A Misc/NEWS.d/next/Library/2019-08-31-13-36-09.bpo-37995.rS8HzT.rst
M Doc/library/ast.rst
M Doc/whatsnew/3.9.rst
M Lib/ast.py
M Lib/test/test_ast.py
diff --git a/Doc/library/ast.rst b/Doc/library/ast.rst
index 92bf8912eb53..cb8e7ec829be 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 5670cb59f481..deaefc753916 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
---------
diff --git a/Lib/ast.py b/Lib/ast.py
index 5ab023f6c3c0..498484f19855 100644
--- a/Lib/ast.py
+++ b/Lib/ast.py
@@ -96,7 +96,7 @@ def _convert(node):
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 _format(node):
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 07bbb4cc7723..47e259eb2656 100644
--- a/Lib/test/test_ast.py
+++ b/Lib/test/test_ast.py
@@ -645,6 +645,68 @@ def test_dump(self):
"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 000000000000..19482b644e14
--- /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.
More information about the Python-checkins
mailing list