From 9bd0c900936828c84817865727be224b5c44d13d 2012-07-08 04:22:47
From: Aaron Meurer <asmeurer@gmail.com>
Date: 2012-07-08 04:22:47
Subject: [PATCH] Line continuations now terminate after one blank line (#2108)
Previously, we had
In [1]: 1\
...:
...:
...:
...:
In other words, no amount of blank lines would terminate after a line
continuation, in contrast with regular Python:
>>> 1\
...
1
This made things really annoying when I typed \ instead of a newline--quite
easy to do since they are right next to each other on the keyboard.
Now, we have
In [1]: 1\
...:
Out[1]: 1
This also fixes another related behavioral difference between IPython. If a
space follows a line continuation character, it should be a
SyntaxError("unexpected character after line continuation character"), even if
the line is otherwise continuable, according to regular Python (e.g., `1 \ `
or `(1 + \ `). This now consistent between the two.
Closes #2108
---
diff --git a/IPython/core/inputsplitter.py b/IPython/core/inputsplitter.py
index f00cff0..18ac736 100644
--- a/IPython/core/inputsplitter.py
+++ b/IPython/core/inputsplitter.py
@@ -202,17 +202,17 @@ def remove_comments(src):
"""
return re.sub('#.*', '', src)
-
+
def has_comment(src):
"""Indicate whether an input line has (i.e. ends in, or is) a comment.
-
+
This uses tokenize, so it can distinguish comments from # inside strings.
-
+
Parameters
----------
src : string
A single line input string.
-
+
Returns
-------
Boolean: True if source has a comment.
@@ -280,9 +280,9 @@ class InputSplitter(object):
code = None
# Input mode
input_mode = 'line'
-
+
# Private attributes
-
+
# List with lines of input accumulated so far
_buffer = None
# Command compiler
@@ -291,7 +291,7 @@ class InputSplitter(object):
_full_dedent = False
# Boolean indicating whether the current block is complete
_is_complete = None
-
+
def __init__(self, input_mode=None):
"""Create a new InputSplitter instance.
@@ -348,7 +348,7 @@ class InputSplitter(object):
----------
lines : string
One or more lines of Python input.
-
+
Returns
-------
is_complete : boolean
@@ -359,7 +359,7 @@ class InputSplitter(object):
"""
if self.input_mode == 'cell':
self.reset()
-
+
self._store(lines)
source = self.source
@@ -369,7 +369,7 @@ class InputSplitter(object):
self.code, self._is_complete = None, None
# Honor termination lines properly
- if source.rstrip().endswith('\\'):
+ if source.endswith('\\\n'):
return False
self._update_indent(lines)
@@ -400,11 +400,11 @@ class InputSplitter(object):
SyntaxError is raised, or *all* of the following are true:
1. The input compiles to a complete statement.
-
+
2. The indentation level is flush-left (because if we are indented,
like inside a function definition or for loop, we need to keep
reading new input).
-
+
3. There is one extra line consisting only of whitespace.
Because of condition #3, this method should be used only by
@@ -464,7 +464,7 @@ class InputSplitter(object):
----------
line : str
A single new line of non-whitespace, non-comment Python input.
-
+
Returns
-------
indent_spaces : int
@@ -476,7 +476,7 @@ class InputSplitter(object):
"""
indent_spaces = self.indent_spaces
full_dedent = self._full_dedent
-
+
inisp = num_ini_spaces(line)
if inisp < indent_spaces:
indent_spaces = inisp
@@ -495,9 +495,9 @@ class InputSplitter(object):
if indent_spaces < 0:
indent_spaces = 0
#print 'safety' # dbg
-
+
return indent_spaces, full_dedent
-
+
def _update_indent(self, lines):
for line in remove_comments(lines).splitlines():
if line and not line.isspace():
@@ -508,10 +508,10 @@ class InputSplitter(object):
If input lines are not newline-terminated, a newline is automatically
appended."""
-
+
if buffer is None:
buffer = self._buffer
-
+
if lines.endswith('\n'):
buffer.append(lines)
else:
@@ -627,10 +627,10 @@ def transform_help_end(line):
target = m.group(1)
esc = m.group(3)
lspace = _initial_space_re.match(line).group(0)
-
+
# If we're mid-command, put it back on the next prompt for the user.
next_input = line.rstrip('?') if line.strip() != m.group(0) else None
-
+
return _make_help_call(target, esc, lspace, next_input)
@@ -647,7 +647,7 @@ class EscapedTransformer(object):
ESC_QUOTE2 : self._tr_quote2,
ESC_PAREN : self._tr_paren }
self.tr = tr
-
+
# Support for syntax transformations that use explicit escapes typed by the
# user at the beginning of a line
@staticmethod
@@ -668,7 +668,7 @@ class EscapedTransformer(object):
# A naked help line should just fire the intro help screen
if not line_info.line[1:]:
return 'get_ipython().show_usage()'
-
+
return _make_help_call(line_info.ifun, line_info.esc, line_info.pre)
@staticmethod
@@ -745,7 +745,7 @@ class IPythonInputSplitter(InputSplitter):
super(IPythonInputSplitter, self).__init__(input_mode)
self._buffer_raw = []
self._validate = True
-
+
def reset(self):
"""Reset the input buffer and associated state."""
super(IPythonInputSplitter, self).reset()
@@ -897,7 +897,7 @@ class IPythonInputSplitter(InputSplitter):
# that this must be done *after* the reset() call that would otherwise
# flush the buffer.
self._store(lines, self._buffer_raw, 'source_raw')
-
+
try:
push = super(IPythonInputSplitter, self).push
buf = self._buffer
diff --git a/IPython/core/tests/test_inputsplitter.py b/IPython/core/tests/test_inputsplitter.py
index 08e0848..865855a 100644
--- a/IPython/core/tests/test_inputsplitter.py
+++ b/IPython/core/tests/test_inputsplitter.py
@@ -351,6 +351,22 @@ class InputSplitterTestCase(unittest.TestCase):
self.isp.push(u'\xc3\xa9')
self.isp.push(u"u'\xc3\xa9'")
+ def test_line_continuation(self):
+ """ Test issue #2108."""
+ isp = self.isp
+ # A blank line after a line continuation should not accept more
+ isp.push("1 \\\n\n")
+ self.assertFalse(isp.push_accepts_more())
+ # Whitespace after a \ is a SyntaxError. The only way to test that
+ # here is to test that push doesn't accept more (as with
+ # test_syntax_error() above).
+ isp.push(r"1 \ ")
+ self.assertFalse(isp.push_accepts_more())
+ # Even if the line is continuable (c.f. the regular Python
+ # interpreter)
+ isp.push(r"(1 \ ")
+ self.assertFalse(isp.push_accepts_more())
+
class InteractiveLoopTestCase(unittest.TestCase):
"""Tests for an interactive loop like a python shell.
"""
@@ -678,7 +694,7 @@ class BlockIPythonInputTestCase(IPythonInputTestCase):
def test_syntax_multiline_cell(self):
isp = self.isp
for example in syntax_ml.itervalues():
-
+
out_t_parts = []
for line_pairs in example:
raw = '\n'.join(r for r, _ in line_pairs)
@@ -762,7 +778,7 @@ def test_last_two_blanks():
class CellMagicsCommon(object):
-
+
def test_whole_cell(self):
src = "%%cellm line\nbody\n"
sp = self.sp