first commit

utils.py

@@ -0,0 +1,28 @@
+import re
+import sys
+
+_URL_PLACEHOLDER_PATTERN = re.compile('<(.*?)>')
+
+
+def get_pipe(name):
+    """通过 mod.ClassName 导入自定义的PipeHandler"""
+    module_name, obj_name = name.rsplit('.', 1)
+    __import__(module_name)
+    module = sys.modules[module_name]
+    obj = getattr(module, obj_name)
+    return obj
+
+
+def extract_placeholders(url):
+    """
+    >>> res = extract_placeholders("/<service_name>/resource/<resource_id>/submit/")
+    >>> assert set(res) == {"service_name", "resource_id"}
+    :param url: request url name
+    :return: list of placeholder name
+    """
+    return _URL_PLACEHOLDER_PATTERN.findall(url)
+
+
+def replace_placeholder(url, placeholder_name, value):
+    return url.replace('<{}>'.format(placeholder_name), str(value))
+