# Copyright 2006 Google, Inc. All Rights Reserved. # Licensed to PSF under a Contributor Agreement. """Fixer for has_key(). Calls to .has_key() methods are expressed in terms of the 'in' operator: d.has_key(k) -> k in d CAVEATS: 1) While the primary target of this fixer is dict.has_key(), the fixer will change any has_key() method call, regardless of its class. 2) Cases like this will not be converted: m = d.has_key if m(k): ... Only *calls* to has_key() are converted. While it is possible to convert the above to something like m = d.__contains__ if m(k): ... this is currently not done. """ # Local imports from .. import pytree from .. import fixer_base from ..fixer_util import Name, parenthesize class FixHasKey(fixer_base.BaseFix): BM_compatible = True PATTERN = """ anchor=power< before=any+ trailer< '.' 'has_key' > trailer< '(' ( not(arglist | argument) arg=any ','> ) ')' > after=any* > | negation=not_test< 'not' anchor=power< before=any+ trailer< '.' 'has_key' > trailer< '(' ( not(arglist | argument) arg=any ','> ) ')' > > > """ def transform(self, node, results): assert results syms = self.syms if (node.parent.type == syms.not_test and self.pattern.match(node.parent)): # Don't transform a node matching the first alternative of the # pattern when its parent matches the second alternative return None negation = results.get("negation") anchor = results["anchor"] prefix = node.prefix before = [n.clone() for n in results["before"]] arg = results["arg"].clone() after = results.get("after") if after: after = [n.clone() for n in after] if arg.type in (syms.comparison, syms.not_test, syms.and_test, syms.or_test, syms.test, syms.lambdef, syms.argument): arg = parenthesize(arg) if len(before) == 1: before = before[0] else: before = pytree.Node(syms.power, before) before.prefix = " " n_op = Name("in", prefix=" ") if negation: n_not = Name("not", prefix=" ") n_op = pytree.Node(syms.comp_op, (n_not, n_op)) new = pytree.Node(syms.comparison, (arg, n_op, before)) if after: new = parenthesize(new) new = pytree.Node(syms.power, (new,) + tuple(after)) if node.parent.type in (syms.comparison, syms.expr, syms.xor_expr, syms.and_expr, syms.shift_expr, syms.arith_expr, syms.term, syms.factor, syms.power): new = parenthesize(new) new.prefix = prefix return new