File Content: fix_print.py # Copyright 2006 Google, Inc. All Rights Reserved. # Licensed to PSF under a Contributor Agreement. """Fixer for print. Change: "print" into "print()" "print ..." into "print(...)" "print(...)" not changed "print ... ," into "print(..., end=' ')" "print >>x, ..." into "print(..., file=x)" No changes are applied if print_function is imported from __future__ """ # Local imports from lib2to3 import patcomp, pytree, fixer_base from lib2to3.pgen2 import token from lib2to3.fixer_util import Name, Call, Comma, String # from libmodernize import add_future parend_expr = patcomp.compile_pattern( """atom< '(' [arith_expr|atom|power|term|STRING|NAME] ')' >""" ) class FixPrint(fixer_base.BaseFix): BM_compatible = True PATTERN = """ simple_stmt< any* bare='print' any* > | print_stmt """ def transform(self, node, results): assert results bare_print = results.get("bare") if bare_print: # Special-case print all by itself. bare_print.replace(Call(Name(u"print"), [], prefix=bare_print.prefix)) # The "from __future__ import print_function"" declaration is added # by the fix_print_with_import fixer, so we skip it here. # add_future(node, u'print_function') return assert node.children[0] == Name(u"print") args = node.children[1:] if len(args) == 1 and parend_expr.match(args[0]): # We don't want to keep sticking parens around an # already-parenthesised expression. return sep = end = file = None if args and args[-1] == Comma(): args = args[:-1] end = " " if args and args[0] == pytree.Leaf(token.RIGHTSHIFT, u">>"): assert len(args) >= 2 file = args[1].clone() args = args[3:] # Strip a possible comma after the file expression # Now synthesize a print(args, sep=..., end=..., file=...) node. l_args = [arg.clone() for arg in args] if l_args: l_args[0].prefix = u"" if sep is not None or end is not None or file is not None: if sep is not None: self.add_kwarg(l_args, u"sep", String(repr(sep))) if end is not None: self.add_kwarg(l_args, u"end", String(repr(end))) if file is not None: self.add_kwarg(l_args, u"file", file) n_stmt = Call(Name(u"print"), l_args) n_stmt.prefix = node.prefix # Note that there are corner cases where adding this future-import is # incorrect, for example when the file also has a 'print ()' statement # that was intended to print "()". # add_future(node, u'print_function') return n_stmt def add_kwarg(self, l_nodes, s_kwd, n_expr): # XXX All this prefix-setting may lose comments (though rarely) n_expr.prefix = u"" n_argument = pytree.Node(self.syms.argument, (Name(s_kwd), pytree.Leaf(token.EQUAL, u"="), n_expr)) if l_nodes: l_nodes.append(Comma()) n_argument.prefix = u" " l_nodes.append(n_argument) Submit