[Python-checkins] [2.7] bpo-33899: Make tokenize module mirror end-of-file is end-of-line behavior (GH-7891) (#8133)
Tal Einat
webhook-mailer at python.org
Fri Jul 6 06:23:16 EDT 2018
https://github.com/python/cpython/commit/7829bba45d0e2446f3a0ca240bfe46959f01071e
commit: 7829bba45d0e2446f3a0ca240bfe46959f01071e
branch: 2.7
author: Ammar Askar <ammar_askar at hotmail.com>
committer: Tal Einat <taleinat+github at gmail.com>
date: 2018-07-06T13:23:13+03:00
summary:
[2.7] bpo-33899: Make tokenize module mirror end-of-file is end-of-line behavior (GH-7891) (#8133)
Most of the change involves fixing up the test suite, which previously made
the assumption that there wouldn't be a new line if the input didn't end in
one.
Contributed by Ammar Askar.
(cherry picked from commit c4ef4896eac86a6759901c8546e26de4695a1389)
files:
A Misc/NEWS.d/next/Library/2018-06-24-01-57-14.bpo-33899.IaOcAr.rst
M Lib/test/test_tokenize.py
M Lib/tokenize.py
diff --git a/Lib/test/test_tokenize.py b/Lib/test/test_tokenize.py
index fd9486bdd7d3..a4625971d378 100644
--- a/Lib/test/test_tokenize.py
+++ b/Lib/test/test_tokenize.py
@@ -1,32 +1,54 @@
from test import test_support
-from tokenize import (untokenize, generate_tokens, NUMBER, NAME, OP,
+from tokenize import (untokenize, generate_tokens, NUMBER, NAME, OP, NEWLINE,
STRING, ENDMARKER, tok_name, Untokenizer, tokenize)
from StringIO import StringIO
import os
from unittest import TestCase
+# Converts a source string into a list of textual representation
+# of the tokens such as:
+# ` NAME 'if' (1, 0) (1, 2)`
+# to make writing tests easier.
+def stringify_tokens_from_source(token_generator, source_string):
+ result = []
+ num_lines = len(source_string.splitlines())
+ missing_trailing_nl = source_string[-1] not in '\r\n'
+
+ for type, token, start, end, line in token_generator:
+ if type == ENDMARKER:
+ break
+ # Ignore the new line on the last line if the input lacks one
+ if missing_trailing_nl and type == NEWLINE and end[0] == num_lines:
+ continue
+ type = tok_name[type]
+ result.append(" %(type)-10.10s %(token)-13.13r %(start)s %(end)s" %
+ locals())
+
+ return result
+
class TokenizeTest(TestCase):
# Tests for the tokenize module.
# The tests can be really simple. Given a small fragment of source
- # code, print out a table with tokens. The ENDMARKER is omitted for
- # brevity.
+ # code, print out a table with tokens. The ENDMARKER, ENCODING and
+ # final NEWLINE are omitted for brevity.
def check_tokenize(self, s, expected):
# Format the tokens in s in a table format.
- # The ENDMARKER is omitted.
- result = []
f = StringIO(s)
- for type, token, start, end, line in generate_tokens(f.readline):
- if type == ENDMARKER:
- break
- type = tok_name[type]
- result.append(" %(type)-10.10s %(token)-13.13r %(start)s %(end)s" %
- locals())
+ result = stringify_tokens_from_source(generate_tokens(f.readline), s)
+
self.assertEqual(result,
expected.rstrip().splitlines())
+ def test_implicit_newline(self):
+ # Make sure that the tokenizer puts in an implicit NEWLINE
+ # when the input lacks a trailing new line.
+ f = StringIO("x")
+ tokens = list(generate_tokens(f.readline))
+ self.assertEqual(tokens[-2][0], NEWLINE)
+ self.assertEqual(tokens[-1][0], ENDMARKER)
def test_basic(self):
self.check_tokenize("1 + 1", """\
@@ -616,7 +638,7 @@ def test_roundtrip(self):
self.check_roundtrip("if x == 1:\n"
" print x\n")
self.check_roundtrip("# This is a comment\n"
- "# This also")
+ "# This also\n")
# Some people use different formatting conventions, which makes
# untokenize a little trickier. Note that this test involves trailing
diff --git a/Lib/tokenize.py b/Lib/tokenize.py
index d426cd2df52a..6c857f854733 100644
--- a/Lib/tokenize.py
+++ b/Lib/tokenize.py
@@ -306,8 +306,15 @@ def generate_tokens(readline):
contline = None
indents = [0]
+ last_line = b''
+ line = b''
while 1: # loop over lines in stream
try:
+ # We capture the value of the line variable here because
+ # readline uses the empty string '' to signal end of input,
+ # hence `line` itself will always be overwritten at the end
+ # of this loop.
+ last_line = line
line = readline()
except StopIteration:
line = ''
@@ -437,6 +444,9 @@ def generate_tokens(readline):
(lnum, pos), (lnum, pos+1), line)
pos += 1
+ # Add an implicit NEWLINE if the input doesn't end in one
+ if last_line and last_line[-1] not in '\r\n':
+ yield (NEWLINE, '', (lnum - 1, len(last_line)), (lnum - 1, len(last_line) + 1), '')
for indent in indents[1:]: # pop remaining indent levels
yield (DEDENT, '', (lnum, 0), (lnum, 0), '')
yield (ENDMARKER, '', (lnum, 0), (lnum, 0), '')
diff --git a/Misc/NEWS.d/next/Library/2018-06-24-01-57-14.bpo-33899.IaOcAr.rst b/Misc/NEWS.d/next/Library/2018-06-24-01-57-14.bpo-33899.IaOcAr.rst
new file mode 100644
index 000000000000..21c909599363
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2018-06-24-01-57-14.bpo-33899.IaOcAr.rst
@@ -0,0 +1,3 @@
+Tokenize module now implicitly emits a NEWLINE when provided with input that
+does not have a trailing new line. This behavior now matches what the C
+tokenizer does internally. Contributed by Ammar Askar.
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