Use .format_map for safe formatting

maxpoletaev · Apr 17, 2016 · 952e1f0 · 952e1f0
1 parent 82f2a92
commit 952e1f0
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Showing 2 changed files with 9 additions and 7 deletions.
diff --git a/langpack/utils.py b/langpack/utils.py
@@ -1,14 +1,13 @@
 from importlib import import_module
 
 
+class safedict(dict):
+    def __missing__(self, key):
+        return '{' + key + '}'
+
+
 def safe_format(source, **kwargs):
-    # TODO: perfomance problem
-    while True:
-        try:
-            return source.format(**kwargs)
-        except KeyError as e:
-            e = e.args[0]
-            kwargs[e] = '{%s}' % e
+    return source.format_map(safedict(**kwargs))
 
 
 def import_class(path):

diff --git a/tests/test_translators.py b/tests/test_translators.py
@@ -36,6 +36,9 @@ def test_translate(self):
         result = self.translator.translate('hello', name='John')
         test.assert_equal(result, 'Hello, John!')
 
+        result = self.translator.translate('hello')
+        test.assert_equal(result, 'Hello, {name}!')
+
         result = self.translator.translate('i_have_apples', count=0)
         test.assert_equal(result, 'I have no apples')