1 files changed, 81 insertions, 0 deletions
diff --git a/Lib/lib2to3/fixes/fix_print.py b/Lib/lib2to3/fixes/fix_print.py
new file mode 100644
index 0000000..aa5c60a
--- /dev/null
+++ b/Lib/lib2to3/fixes/fix_print.py
@@ -0,0 +1,81 @@
+# 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 ... ,'    into 'print(..., end=" ")'
+    'print >>x, ...' into 'print(..., file=x)'
+"""
+
+# Local imports
+from .. import patcomp
+from .. import pytree
+from ..pgen2 import token
+from .import basefix
+from .util import Name, Call, Comma, String, is_tuple
+
+
+parend_expr = patcomp.compile_pattern(
+              """atom< '(' [atom|STRING|NAME] ')' >"""
+              )
+
+
+class FixPrint(basefix.BaseFix):
+
+    PATTERN = """
+              simple_stmt< 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("print"), [],
+                               prefix=bare_print.get_prefix()))
+            return
+        assert node.children[0] == Name("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, ">>"):
+            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].set_prefix("")
+        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, "sep", String(repr(sep)))
+            if end is not None:
+                self.add_kwarg(l_args, "end", String(repr(end)))
+            if file is not None:
+                self.add_kwarg(l_args, "file", file)
+        n_stmt = Call(Name("print"), l_args)
+        n_stmt.set_prefix(node.get_prefix())
+        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.set_prefix("")
+        n_argument = pytree.Node(self.syms.argument,
+                                 (Name(s_kwd),
+                                  pytree.Leaf(token.EQUAL, "="),
+                                  n_expr))
+        if l_nodes:
+            l_nodes.append(Comma())
+            n_argument.set_prefix(" ")
+        l_nodes.append(n_argument)