Minor code modernisations in Tempita module to use the with-statement.

Cython/Tempita/_tempita.py

@@ -146,9 +146,8 @@ class Template(object):
 
     def from_filename(cls, filename, namespace=None, encoding=None,
                       default_inherit=None, get_template=get_file_template):
-        f = open(filename, 'rb')
+        with open(filename, 'rb') as f:
             c = f.read()
-        f.close()
         if encoding:
             c = c.decode(encoding)
         return cls(content=c, name=filename, namespace=namespace,
@@ -1164,9 +1163,8 @@ def fill_command(args=None):
         template_content = sys.stdin.read()
         template_name = '<stdin>'
     else:
-        f = open(template_name, 'rb')
+        with open(template_name, 'rb') as f:
             template_content = f.read()
-        f.close()
     if options.use_html:
         TemplateClass = HTMLTemplate
     else:
@@ -1174,9 +1172,8 @@ def fill_command(args=None):
     template = TemplateClass(template_content, name=template_name)
     result = template.substitute(vars)
     if options.output:
-        f = open(options.output, 'wb')
+        with open(options.output, 'wb') as f:
             f.write(result)
-        f.close()
     else:
         sys.stdout.write(result)