At the cost of a modest (but useful in its own right) change in the semantics

of the Template.delimiter attribute, we make use of the delimiter in the
escaped group, and in the safe_substitute() method more robust.

Now, .delimiter should be the unescaped delimiter literal, e.g. '$' or '&', or
whatever.  The _TemplateMetaclass will re.escape() this value when it builds
the pattern.
This commit is contained in:
Barry Warsaw 2004-09-18 00:06:34 +00:00
parent 2e6fb4634c
commit 17cb60083c
1 changed files with 6 additions and 8 deletions

View File

@ -113,7 +113,7 @@ class _TemplateMetaclass(type):
pattern = cls.pattern
else:
pattern = _TemplateMetaclass.pattern % {
'delim' : cls.delimiter,
'delim' : _re.escape(cls.delimiter),
'id' : cls.idpattern,
}
cls.pattern = _re.compile(pattern, _re.IGNORECASE | _re.VERBOSE)
@ -123,7 +123,7 @@ class Template:
"""A string class for supporting $-substitutions."""
__metaclass__ = _TemplateMetaclass
delimiter = r'\$'
delimiter = '$'
idpattern = r'[_a-z][_a-z0-9]*'
def __init__(self, template):
@ -152,7 +152,6 @@ class Template:
mapping = _multimap(kws, args[0])
else:
mapping = args[0]
delimiter = self.delimiter[-1]
# Helper function for .sub()
def convert(mo):
# Check the most common path first.
@ -163,7 +162,7 @@ class Template:
# fail if val is a Unicode containing non-ASCII characters.
return '%s' % val
if mo.group('escaped') is not None:
return delimiter
return self.delimiter
if mo.group('invalid') is not None:
self._invalid(mo)
raise ValueError('Unrecognized named group in pattern', pattern)
@ -178,7 +177,6 @@ class Template:
mapping = _multimap(kws, args[0])
else:
mapping = args[0]
delimiter = self.delimiter[-1]
# Helper function for .sub()
def convert(mo):
named = mo.group('named')
@ -188,15 +186,15 @@ class Template:
# will fail if val is a Unicode containing non-ASCII
return '%s' % mapping[named]
except KeyError:
return delimiter + named
return self.delimiter + named
braced = mo.group('braced')
if braced is not None:
try:
return '%s' % mapping[braced]
except KeyError:
return delimiter + '{' + braced + '}'
return self.delimiter + '{' + braced + '}'
if mo.group('escaped') is not None:
return delimiter
return self.delimiter
if mo.group('invalid') is not None:
self._invalid(mo)
raise ValueError('Unrecognized named group in pattern', pattern)