PEP 3101: Completed string.Formatter class. Reimplemented field_name to object transformation.
diff --git a/Lib/string.py b/Lib/string.py
index 9df78af..edf5ae2 100644
--- a/Lib/string.py
+++ b/Lib/string.py
@@ -200,31 +200,59 @@
# exposed here via the sys module. sys was chosen because it's always
# available and doesn't have to be dynamically loaded.
-# The parser is implemented in sys._formatter_parser.
-# The "object lookup" is implemented in sys._formatter_lookup
+# The overall parser is implemented in sys._formatter_parser.
+# The field name parser is implemented in sys._formatter_field_name_split
-from sys import _formatter_parser, _formatter_lookup
+from sys import _formatter_parser, _formatter_field_name_split
class Formatter:
def format(self, format_string, *args, **kwargs):
return self.vformat(format_string, args, kwargs)
def vformat(self, format_string, args, kwargs):
+ used_args = set()
result = []
for (is_markup, literal, field_name, format_spec, conversion) in \
_formatter_parser(format_string):
if is_markup:
- # find the object
- index, name, obj = _formatter_lookup(field_name, args, kwargs)
+ # given the field_name, find the object it references
+
+ # split it into the first part, and and iterator that
+ # looks over the rest
+ first, rest = _formatter_field_name_split(field_name)
+
+ used_args.add(first)
+ obj = self.get_value(first, args, kwargs)
+
+ # loop through the rest of the field_name, doing
+ # getattr or getitem as needed
+ for is_attr, i in rest:
+ if is_attr:
+ obj = getattr(obj, i)
+ else:
+ obj = obj[i]
+
+ # do any conversion on the resulting object
+ if conversion == 'r':
+ obj = repr(obj)
+ elif conversion == 's':
+ obj = str(obj)
+
+ # format the object and append to the result
+ result.append(self.format_field(obj, format_spec))
else:
result.append(literal)
+ self.check_unused_args(used_args, args, kwargs)
return ''.join(result)
def get_value(self, key, args, kwargs):
- pass
+ if isinstance(key, int):
+ return args[key]
+ else:
+ return kwargs[key]
def check_unused_args(self, used_args, args, kwargs):
pass
def format_field(self, value, format_spec):
- pass
+ return format(value, format_spec)