[Python-checkins] cpython (merge 3.6 -> default): Merge with 3.6
jason.coombs
python-checkins at python.org
Sun Nov 6 11:27:58 EST 2016
https://hg.python.org/cpython/rev/f332032b1934
changeset: 104929:f332032b1934
parent: 104926:5fda909c722c
parent: 104928:d9eb609be2ca
user: Jason R. Coombs <jaraco at jaraco.com>
date: Sun Nov 06 11:27:50 2016 -0500
summary:
Merge with 3.6
files:
Doc/reference/lexical_analysis.rst | 19 +++++++++++------
Lib/test/test_fstring.py | 13 +++++++----
2 files changed, 20 insertions(+), 12 deletions(-)
diff --git a/Doc/reference/lexical_analysis.rst b/Doc/reference/lexical_analysis.rst
--- a/Doc/reference/lexical_analysis.rst
+++ b/Doc/reference/lexical_analysis.rst
@@ -679,17 +679,22 @@
A consequence of sharing the same syntax as regular string literals is
that characters in the replacement fields must not conflict with the
-quoting used in the outer formatted string literal. Also, escape
-sequences normally apply to the outer formatted string literal,
-rather than inner string literals::
+quoting used in the outer formatted string literal::
f"abc {a["x"]} def" # error: outer string literal ended prematurely
- f"abc {a[\"x\"]} def" # workaround: escape the inner quotes
f"abc {a['x']} def" # workaround: use different quoting
- f"newline: {ord('\n')}" # error: literal line break in inner string
- f"newline: {ord('\\n')}" # workaround: double escaping
- fr"newline: {ord('\n')}" # workaround: raw outer string
+Backslashes are not allowed in format expressions and will raise
+an error::
+
+ f"newline: {ord('\n')}" # raises SyntaxError
+
+To include a value in which a backslash escape is required, create
+a temporary variable.
+
+ >>> newline = ord('\n')
+ >>> f"newline: {newline}"
+ 'newline: 10'
See also :pep:`498` for the proposal that added formatted string literals,
and :meth:`str.format`, which uses a related format string mechanism.
diff --git a/Lib/test/test_fstring.py b/Lib/test/test_fstring.py
--- a/Lib/test/test_fstring.py
+++ b/Lib/test/test_fstring.py
@@ -382,11 +382,14 @@
])
def test_no_escapes_for_braces(self):
- # \x7b is '{'. Make sure it doesn't start an expression.
- self.assertEqual(f'\x7b2}}', '{2}')
- self.assertEqual(f'\x7b2', '{2')
- self.assertEqual(f'\u007b2', '{2')
- self.assertEqual(f'\N{LEFT CURLY BRACKET}2\N{RIGHT CURLY BRACKET}', '{2}')
+ """
+ Only literal curly braces begin an expression.
+ """
+ # \x7b is '{'.
+ self.assertEqual(f'\x7b1+1}}', '{1+1}')
+ self.assertEqual(f'\x7b1+1', '{1+1')
+ self.assertEqual(f'\u007b1+1', '{1+1')
+ self.assertEqual(f'\N{LEFT CURLY BRACKET}1+1\N{RIGHT CURLY BRACKET}', '{1+1}')
def test_newlines_in_expressions(self):
self.assertEqual(f'{0}', '0')
--
Repository URL: https://hg.python.org/cpython
More information about the Python-checkins
mailing list