Update of /cvsroot/docstring/dps/dps
In directory usw-pr-cvs1:/tmp/cvs-serv18456/dps/dps
Modified Files:
utils.py
Log Message:
- Added 'parseattributes()', associated functions and exceptions.
Index: utils.py
===================================================================
RCS file: /cvsroot/docstring/dps/dps/utils.py,v
retrieving revision 1.7
retrieving revision 1.8
diff -C2 -d -r1.7 -r1.8
*** utils.py 2001/09/18 04:32:12 1.7
--- utils.py 2001/11/15 02:57:22 1.8
***************
*** 58,59 ****
--- 58,171 ----
def severe(self, comment=None, children=[]):
return self.system_warning(3, comment, children)
+
+
+ class AttributeParsingError(Exception): pass
+ class BadAttributeLineError(AttributeParsingError): pass
+ class BadAttributeDataError(AttributeParsingError): pass
+ class DuplicateAttributeError(AttributeParsingError): pass
+
+
+ def parseattributes(lines, attributespec):
+ """
+ Return a dictionary mapping attribute names to converted values.
+
+ :Parameters:
+ - `lines`: List of one-line strings of the form::
+
+ ['[name1=value1 name2=value2]', '[name3="value 3"]']
+
+ - `attributespec`: Dictionary mapping known attribute names to a
+ conversion function such as `int` or `float`.
+
+ :Raises:
+ - `KeyError` for unknown attribute names.
+ - `ValueError` for invalid attribute values (raised by conversion
+ function).
+ - `DuplicateAttributeError` for duplicate attributes.
+ - `BadAttributeLineError` for input lines not enclosed in brackets.
+ - `BadAttributeDataError` for invalid attribute data (missing name,
+ missing data, bad quotes, etc.).
+ """
+ attlist = extractattributes(lines)
+ attdict = assembleattributes(attlist, attributespec)
+ return attdict
+
+ def extractattributes(lines):
+ """
+ Return a list of attribute (name, value) pairs.
+
+ :Parameter:
+ `lines`: List of one-line strings of the form::
+
+ ['[name1=value1 name2=value2]', '[name3="value 3"]']
+
+ :Raises:
+ - `BadAttributeLineError` for input lines not enclosed in brackets.
+ - `BadAttributeDataError` for invalid attribute data (missing name,
+ missing data, bad quotes, etc.).
+ """
+ attlist = []
+ for line in lines:
+ line = line.strip()
+ if line[:1] != '[' or line[-1:] != ']':
+ raise BadAttributeLineError(
+ 'input line not enclosed in "[" and "]"')
+ line = line[1:-1].strip()
+ while line:
+ equals = line.find('=')
+ if equals == -1:
+ raise BadAttributeDataError('missing "="')
+ elif equals == 0:
+ raise BadAttributeDataError(
+ 'missing attribute name before "="')
+ attname = line[:equals]
+ line = line[equals+1:]
+ if not line:
+ raise BadAttributeDataError(
+ 'missing value after "%s="' % attname)
+ if line[0] in '\'"':
+ endquote = line.find(line[0], 1)
+ if endquote == -1:
+ raise BadAttributeDataError(
+ 'attribute "%s" missing end quote (%s)'
+ % (attname, line[0]))
+ if len(line) > endquote + 1 and line[endquote + 1].strip():
+ raise BadAttributeDataError(
+ 'attribute "%s" end quote (%s) not followed by '
+ 'whitespace' % (attname, line[0]))
+ data = line[1:endquote]
+ line = line[endquote+1:].lstrip()
+ else:
+ space = line.find(' ')
+ if space == -1:
+ data = line
+ line = ''
+ else:
+ data = line[:space]
+ line = line[space+1:].lstrip()
+ attlist.append((attname.lower(), data))
+ return attlist
+
+ def assembleattributes(attlist, attributespec):
+ """
+ Return a mapping of attribute names to values.
+
+ :Parameters:
+ - `attlist`: A list of (name, value) pairs (the output of
+ `extractattributes()`).
+ - `attributespec`: Dictionary mapping known attribute names to a
+ conversion function such as `int` or `float`.
+
+ :Raises:
+ - `KeyError` for unknown attribute names.
+ - `DuplicateAttributeError` for duplicate attributes.
+ - `ValueError` for invalid attribute values (raised by conversion
+ function).
+ """
+ attributes = {}
+ for name, value in attlist:
+ convertor = attributespec[name] # raises KeyError if unknown
+ if attributes.has_key(name):
+ raise DuplicateAttributeError('duplicate attribute "%s"' % name)
+ attributes[name] = convertor(value) # raises ValueError if invalud
+ return attributes
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