/Lib/lib2to3/fixes/fix_set_literal.py
http://unladen-swallow.googlecode.com/ · Python · 52 lines · 32 code · 11 blank · 9 comment · 4 complexity · 9529989dd16e172f7e7938d49e162a9a MD5 · raw file
- """
- Optional fixer to transform set() calls to set literals.
- """
- # Author: Benjamin Peterson
- from lib2to3 import fixer_base, pytree
- from lib2to3.fixer_util import token, syms
- class FixSetLiteral(fixer_base.BaseFix):
- explicit = True
- PATTERN = """power< 'set' trailer< '('
- (atom=atom< '[' (items=listmaker< any ((',' any)* [',']) >
- |
- single=any) ']' >
- |
- atom< '(' items=testlist_gexp< any ((',' any)* [',']) > ')' >
- )
- ')' > >
- """
- def transform(self, node, results):
- single = results.get("single")
- if single:
- # Make a fake listmaker
- fake = pytree.Node(syms.listmaker, [single.clone()])
- single.replace(fake)
- items = fake
- else:
- items = results["items"]
- # Build the contents of the literal
- literal = [pytree.Leaf(token.LBRACE, "{")]
- literal.extend(n.clone() for n in items.children)
- literal.append(pytree.Leaf(token.RBRACE, "}"))
- # Set the prefix of the right brace to that of the ')' or ']'
- literal[-1].set_prefix(items.get_next_sibling().get_prefix())
- maker = pytree.Node(syms.dictsetmaker, literal)
- maker.set_prefix(node.get_prefix())
- # If the original was a one tuple, we need to remove the extra comma.
- if len(maker.children) == 4:
- n = maker.children[2]
- n.remove()
- maker.children[-1].set_prefix(n.get_prefix())
- # Finally, replace the set call with our shiny new literal.
- return maker