Add pylint to depot_tools.

third_party/pylint/checkers/string_format.py

Index: third_party/pylint/checkers/string_format.py
diff --git a/third_party/pylint/checkers/string_format.py b/third_party/pylint/checkers/string_format.py
new file mode 100644
index 0000000000000000000000000000000000000000..c420a604b74fcf8d7755cc23be8e24f840cad79d
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+++ b/third_party/pylint/checkers/string_format.py
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+# Copyright (c) 2009-2010 Arista Networks, Inc. - James Lingard
+# Copyright (c) 2004-2010 LOGILAB S.A. (Paris, FRANCE).
+# http://www.logilab.fr/ -- mailto:contact@logilab.fr
+# This program is free software; you can redistribute it and/or modify it under
+# the terms of the GNU General Public License as published by the Free Software
+# Foundation; either version 2 of the License, or (at your option) any later
+# version.
+#
+# This program is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+# FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details
+#
+# You should have received a copy of the GNU General Public License along with
+# this program; if not, write to the Free Software Foundation, Inc.,
+# 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+
+
+"""Checker for string formatting operations.
+"""
+
+import string
+from logilab import astng
+from pylint.interfaces import IASTNGChecker
+from pylint.checkers import BaseChecker
+from pylint.checkers import utils
+
+
+MSGS = {
+    'E1300': ("Unsupported format character %r (%#02x) at index %d",
+              "Used when a unsupported format character is used in a format\
+              string."),
+    'E1301': ("Format string ends in middle of conversion specifier",
+              "Used when a format string terminates before the end of a \
+              conversion specifier."),
+    'E1302': ("Mixing named and unnamed conversion specifiers in format string",
+              "Used when a format string contains both named (e.g. '%(foo)d') \
+              and unnamed (e.g. '%d') conversion specifiers.  This is also \
+              used when a named conversion specifier contains * for the \
+              minimum field width and/or precision."),
+    'E1303': ("Expected mapping for format string, not %s",
+              "Used when a format string that uses named conversion specifiers \
+              is used with an argument that is not a mapping."),
+    'W1300': ("Format string dictionary key should be a string, not %s",
+              "Used when a format string that uses named conversion specifiers \
+              is used with a dictionary whose keys are not all strings."),
+    'W1301': ("Unused key %r in format string dictionary",
+              "Used when a format string that uses named conversion specifiers \
+              is used with a dictionary that conWtains keys not required by the \
+              format string."),
+    'E1304': ("Missing key %r in format string dictionary",
+              "Used when a format string that uses named conversion specifiers \
+              is used with a dictionary that doesn't contain all the keys \
+              required by the format string."),
+    'E1305': ("Too many arguments for format string",
+              "Used when a format string that uses unnamed conversion \
+              specifiers is given too few arguments."),
+    'E1306': ("Not enough arguments for format string",
+              "Used when a format string that uses unnamed conversion \
+              specifiers is given too many arguments"),
+    }
+
+OTHER_NODES = (astng.Const, astng.List, astng.Backquote,
+               astng.Lambda, astng.Function,
+               astng.ListComp, astng.SetComp, astng.GenExpr)
+
+class StringFormatChecker(BaseChecker):
+    """Checks string formatting operations to ensure that the format string
+    is valid and the arguments match the format string.
+    """
+
+    __implements__ = (IASTNGChecker,)
+    name = 'string_format'
+    msgs = MSGS
+
+    def visit_binop(self, node):
+        if node.op != '%':
+            return
+        left = node.left
+        args = node.right
+
+        if not (isinstance(left, astng.Const)
+            and isinstance(left.value, basestring)):
+            return
+        format_string = left.value
+        try:
+            required_keys, required_num_args = \
+                utils.parse_format_string(format_string)
+        except utils.UnsupportedFormatCharacter, e:
+            c = format_string[e.index]
+            self.add_message('E1300', node=node, args=(c, ord(c), e.index))
+            return
+        except utils.IncompleteFormatString:
+            self.add_message('E1301', node=node)
+            return
+        if required_keys and required_num_args:
+            # The format string uses both named and unnamed format
+            # specifiers.
+            self.add_message('E1302', node=node)
+        elif required_keys:
+            # The format string uses only named format specifiers.
+            # Check that the RHS of the % operator is a mapping object
+            # that contains precisely the set of keys required by the
+            # format string.
+            if isinstance(args, astng.Dict):
+                keys = set()
+                unknown_keys = False
+                for k, v in args.items:
+                    if isinstance(k, astng.Const):
+                        key = k.value
+                        if isinstance(key, basestring):
+                            keys.add(key)
+                        else:
+                            self.add_message('W1300', node=node, args=key)
+                    else:
+                        # One of the keys was something other than a
+                        # constant.  Since we can't tell what it is,
+                        # supress checks for missing keys in the
+                        # dictionary.
+                        unknown_keys = True
+                if not unknown_keys:
+                    for key in required_keys:
+                        if key not in keys:
+                            self.add_message('E1304', node=node, args=key)
+                for key in keys:
+                    if key not in required_keys:
+                        self.add_message('W1301', node=node, args=key)
+            elif isinstance(args, OTHER_NODES + (astng.Tuple,)):
+                type_name = type(args).__name__
+                self.add_message('E1303', node=node, args=type_name)
+            # else:
+                # The RHS of the format specifier is a name or
+                # expression.  It may be a mapping object, so
+                # there's nothing we can check.
+        else:
+            # The format string uses only unnamed format specifiers.
+            # Check that the number of arguments passed to the RHS of
+            # the % operator matches the number required by the format
+            # string.
+            if isinstance(args, astng.Tuple):
+                num_args = len(args.elts)
+            elif isinstance(args, OTHER_NODES + (astng.Dict, astng.DictComp)):
+                num_args = 1
+            else:
+                # The RHS of the format specifier is a name or
+                # expression.  It could be a tuple of unknown size, so
+                # there's nothing we can check.
+                num_args = None
+            if num_args is not None:
+                if num_args > required_num_args:
+                    self.add_message('E1305', node=node)
+                elif num_args < required_num_args:
+                    self.add_message('E1306', node=node)
+
+
+def register(linter):
+    """required method to auto register this checker """
+    linter.register_checker(StringFormatChecker(linter))