Issue #23671: string.Template now allows to specify the "self" parameter as
keyword argument. string.Formatter now allows to specify the "self" and
the "format_string" parameters as keyword arguments.
diff --git a/Lib/string.py b/Lib/string.py
index d762e04..23608b4 100644
--- a/Lib/string.py
+++ b/Lib/string.py
@@ -145,7 +145,11 @@
raise ValueError('Invalid placeholder in string: line %d, col %d' %
(lineno, colno))
- def substitute(self, *args, **kws):
+ def substitute(*args, **kws):
+ if not args:
+ raise TypeError("descriptor 'substitute' of 'Template' object "
+ "needs an argument")
+ self, args = args[0], args[1:] # allow the "self" keyword be passed
if len(args) > 1:
raise TypeError('Too many positional arguments')
if not args:
@@ -171,7 +175,11 @@
self.pattern)
return self.pattern.sub(convert, self.template)
- def safe_substitute(self, *args, **kws):
+ def safe_substitute(*args, **kws):
+ if not args:
+ raise TypeError("descriptor 'safe_substitute' of 'Template' object "
+ "needs an argument")
+ self, args = args[0], args[1:] # allow the "self" keyword be passed
if len(args) > 1:
raise TypeError('Too many positional arguments')
if not args:
@@ -535,7 +543,19 @@
# The field name parser is implemented in str._formatter_field_name_split
class Formatter(object):
- def format(self, format_string, *args, **kwargs):
+ def format(*args, **kwargs):
+ if not args:
+ raise TypeError("descriptor 'format' of 'Formatter' object "
+ "needs an argument")
+ self, args = args[0], args[1:] # allow the "self" keyword be passed
+ try:
+ format_string, args = args[0], args[1:] # allow the "format_string" keyword be passed
+ except IndexError:
+ if 'format_string' in kwargs:
+ format_string = kwargs.pop('format_string')
+ else:
+ raise TypeError("format() missing 1 required positional "
+ "argument: 'format_string'")
return self.vformat(format_string, args, kwargs)
def vformat(self, format_string, args, kwargs):
diff --git a/Lib/test/test_pep292.py b/Lib/test/test_pep292.py
index 5ff280d..133cab7 100644
--- a/Lib/test/test_pep292.py
+++ b/Lib/test/test_pep292.py
@@ -26,6 +26,7 @@
self.assertEqual(s.substitute(dict(who='tim', what='ham')),
'tim likes to eat a bag of ham worth $100')
self.assertRaises(KeyError, s.substitute, dict(who='tim'))
+ self.assertRaises(TypeError, Template.substitute)
def test_regular_templates_with_braces(self):
s = Template('$who likes ${what} for ${meal}')
@@ -178,6 +179,9 @@
eq(s.substitute(dict(mapping='one'), mapping='two'),
'the mapping is two')
+ s = Template('the self is $self')
+ eq(s.substitute(self='bozo'), 'the self is bozo')
+
def test_keyword_arguments_safe(self):
eq = self.assertEqual
raises = self.assertRaises
@@ -196,6 +200,9 @@
raises(TypeError, s.substitute, d, {})
raises(TypeError, s.safe_substitute, d, {})
+ s = Template('the self is $self')
+ eq(s.safe_substitute(self='bozo'), 'the self is bozo')
+
def test_delimiter_override(self):
eq = self.assertEqual
raises = self.assertRaises
diff --git a/Lib/test/test_string.py b/Lib/test/test_string.py
index e786ab6..fdb3253 100644
--- a/Lib/test/test_string.py
+++ b/Lib/test/test_string.py
@@ -196,6 +196,18 @@
self.assertRaises(ValueError, format, '', '#')
self.assertRaises(ValueError, format, '', '#20')
+ def test_format_keyword_arguments(self):
+ fmt = string.Formatter()
+ self.assertEqual(fmt.format("-{arg}-", arg='test'), '-test-')
+ self.assertRaises(KeyError, fmt.format, "-{arg}-")
+ self.assertEqual(fmt.format("-{self}-", self='test'), '-test-')
+ self.assertRaises(KeyError, fmt.format, "-{self}-")
+ self.assertEqual(fmt.format("-{format_string}-", format_string='test'),
+ '-test-')
+ self.assertRaises(KeyError, fmt.format, "-{format_string}-")
+ self.assertEqual(fmt.format(arg='test', format_string="-{arg}-"),
+ '-test-')
+
class BytesAliasTest(unittest.TestCase):
def test_builtin(self):
diff --git a/Misc/NEWS b/Misc/NEWS
index e9714bb..56eb793 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -21,6 +21,10 @@
Library
-------
+- Issue #23671: string.Template now allows to specify the "self" parameter as
+ keyword argument. string.Formatter now allows to specify the "self" and
+ the "format_string" parameters as keyword arguments.
+
- Issue #21560: An attempt to write a data of wrong type no longer cause
GzipFile corruption. Original patch by Wolfgang Maier.