Add support for Python string formating

Refactor `replace_formatters` to use regex substitution to replace
format strings in both C (previously supported) and now Python.

Add support for Python str.__mod__() and str.format() notation.

msgcheck/po.py

@@ -265,7 +265,7 @@ class PoMessage(object):
                 continue
             text = mstr if spelling == 'str' else mid
             if self.fmt:
-                text = replace_formatters(text, ' ', self.fmt)
+                text = replace_formatters(text, self.fmt)
             checkers[0].set_text(text)
             misspelled = []
             for err in checkers[0]:

msgcheck/utils.py

@@ -24,11 +24,23 @@ Some utility functions for msgcheck.
 from __future__ import print_function
-# TODO: add support for other languages
-STR_FORMATTERS = {
-    'c': ('\\', '%', '#- +\'I.0123456789hlLqjzt', 'diouxXeEfFgGaAcsCSpnm'),
-}
+import re
+from collections import defaultdict
+
+STR_FORMATTERS = defaultdict(list)
+STR_FORMATTERS.update({
+    'c': (
+        (r'[\%]{2}', '%'),
+        (r'\%([ hlL\d\.\-\+\#\*]+)?[cdieEfgGosuxXpn]', r''),
+    ),
+    'python': [
+        (r'[\%]{2}', '%'),
+        (r'\%([.\d]+)?[bcdeEfFgGnosxX]', r''),
+        (r'\%(\(([^)]*)\))([.\d]+)?[bcdeEfFgGnosxX]', r'\g<2>'),
+        (r'\{([^\:\}]*)?(:[^\}]*)?\}', r''),
+    ]
+})
 def count_lines(string):
@@ -39,47 +51,10 @@ def count_lines(string):
     return count
-# pylint: disable=too-many-branches
-def replace_formatters(string, replace, fmt):
-    """
+def replace_formatters(string, fmt):
+    r"""
     Replace formatters (like "%s" or "%03d") with a replacement string.
     """
-    if fmt not in STR_FORMATTERS:
-        return string
-    formatters = STR_FORMATTERS[fmt]
-    formatter, escape = (False, False)
-    strformat = []
-    result = []
-
-    for char in string:
-        if formatter:
-            if char == formatters[1]:
-                result.append(char)
-                formatter = False
-            elif char in formatters[2]:
-                strformat.append(char)
-            elif char in formatters[3]:
-                result.append(replace)
-                formatter = False
-            else:
-                strformat.append(char)
-                result += strformat
-                formatter = False
-        elif escape:
-            result.append(formatters[0])
-            result.append(char)
-            escape = False
-        elif char == formatters[0]:
-            escape = True
-        elif char == formatters[1]:
-            formatter = True
-            strformat = [char]
-        else:
-            result.append(char)
-
-    if escape:  # unterminated escaped char?
-        result.append(formatters[0])
-    elif formatter:  # unterminated formatter?
-        result.append(replace)
-
-    return ''.join(result)
+    for pattern, repl in STR_FORMATTERS[fmt]:
+        string = re.sub(pattern, repl, string)
+    return string

tests/test_msgcheck.py

@@ -96,21 +96,55 @@ class TestMsgCheck(unittest.TestCase):
         # the file has 11 errors (with the fuzzy string)
         self.assertEqual(len(result[0][1]), 11)
-    def test_replace_formatters(self):
-        """Test removal of formatters in a string."""
-        self.assertEqual(replace_formatters('%', '', 'c'), '')
-        self.assertEqual(replace_formatters('\\', '', 'c'), '\\')
-        self.assertEqual(replace_formatters('%s', ' ', 'c'), ' ')
-        self.assertEqual(replace_formatters('%.02f', ' ', 'c'), ' ')
-        self.assertEqual(replace_formatters('%!%s%!', '', 'c'), '%!%!')
-        self.assertEqual(replace_formatters('%.02!', ' ', 'c'), '%.02!')
+    def test_replace_formatters_c(self):
+        """Test removal of formatters in a C string."""
+        self.assertEqual(replace_formatters('%s', 'c'), '')
+        self.assertEqual(replace_formatters('%%', 'c'), '%')
+        self.assertEqual(replace_formatters('%.02f', 'c'), '')
+        self.assertEqual(replace_formatters('%!%s%!', 'c'), '%!%!')
+        self.assertEqual(replace_formatters('%.02!', 'c'), '%.02!')
         self.assertEqual(
-            replace_formatters('%.3fThis is a %stest', ' ', 'c'),
-            ' This is a  test')
+            replace_formatters('%.3fThis is a %stest', 'c'),
+            'This is a test')
         self.assertEqual(
-            replace_formatters('%.3fTest%s%d%%%.03f%luhere% s', '', 'c'),
+            replace_formatters('%.3fTest%s%d%%%.03f%luhere% s', 'c'),
             'Test%here')
+    def test_replace_formatters_python(self):
+        """Test removal of formatters in a python string."""
+        # str.__mod__()
+        self.assertEqual(replace_formatters('%s', 'python'), '')
+        self.assertEqual(replace_formatters('%b', 'python'), '')
+        self.assertEqual(replace_formatters('%%', 'python'), '%')
+        self.assertEqual(replace_formatters('%.02f', 'python'), '')
+        self.assertEqual(replace_formatters('%(sth)s', 'python'), 'sth')
+        self.assertEqual(replace_formatters('%(sth)02f', 'python'), 'sth')
+        # str.format()
+        conditions = [
+            (
+                'First, thou shalt count to {0}', 'First, thou shalt count to ',
+                'References first positional argument'),
+            (
+                'Bring me a {}', 'Bring me a ',
+                'Implicitly references the first positional argument'),
+            ('From {} to {}', 'From  to ', 'Same as "From {0} to {1}"'),
+            (
+                'My quest is {name}', 'My quest is ',
+                'References keyword argument \'name\''),
+            (
+                'Weight in tons {0.weight}', 'Weight in tons ',
+                '\'weight\' attribute of first positional arg'),
+            (
+                'Units destroyed: {players[0]}', 'Units destroyed: ',
+                'First element of keyword argument \'players\'.'),
+        ]
+        for condition in conditions:
+            self.assertEqual(
+                replace_formatters(condition[0], 'python'),
+                condition[1],
+                condition[2],
+            )
+
     def test_spelling_id(self):
         """Test spelling on source messages (English) of gettext files."""
         po_check = PoCheck()