遍历字符串和列表的Python / Django模板

Question

I have an issue with Python/Django where I have either a String or a List of Strings being passed to a Template. If it is a list I need to iterate through it and output each String on a separate line, and if it is a String I just need to output the string. I need to be able to differentiate between the value types and adjust accordingly.

Currently I have code similiar to this:

if isinstance(values, list):
    for value in values:
        html += value + "<br />"
else:
    html += values + "<br />"

My problem is twofold:

Firstly, I am looking for a better/more pythonic way (if possible) to do this which will have the same result. I know that for some situations the isinstance method is not an ideal solution, but would I be able to utilize something like hasattr and would it be an improvement in terms of efficiency?

Secondly, I would ideally want this to be implemented using the Django Template language. If I continue using isinstance or change to hasattr I would have to either make a custom Template filter or tag to be able to pass the proper arguments. Should I forget the template and just write a the code that generates HTML in the view (bad practice) or would the answers to one of these be the best approach for my situation? ( Performing a getattr() style lookup in a django template or django template system, calling a function inside a model )

The current template code can be found here: http://pastebin.com/JK2PRrWv

Background:

I am currently working on some Python(Django) code that implements a simple REST/Json API used to handle queries. One of the requirements is to convert a list of Python dictionaries(parsed from JSON) into very simple HTML tables. To implement this functionality, I have utilized a Django template that takes the list of Python dictionaries and generates HTML from it.

Any help/constructive criticism would be greatly appreciated.

Answer 1

isinstance is probably what you want to distinguish between a string and another iterable, but you should compare with basestring (from which all strings are derived) rather than list. See this question and answer.

if isinstance(values, basestring):
    html += values + "<br />"
else:
    for value in values:
        html += value + "<br />"