blocks|key|2359845|text|就像Ignacio+Vazquez-Abrams在第一条评论中指出的那样，这并不是一种很好的逻辑编码方式。我会确保您的变量具有特定的类型。这可以通过添加到上下文中的额外变量或保存数据的对象以及描述数据类型的内容来解决。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2359846|如果您想坚持您的逻辑，一种可能的方法是编写您自己的模板过滤器(让我们称之为date_or_string)。筛选器可以使用可选的date参数对内置格式筛选器进行子类化。在传递参数的情况下，它的工作方式与普通的date筛选器一样，没有参数，它只返回字符串。在更复杂的场景中，筛选器还可以执行一些类型检查。这只是一个想法，我实际上不会将这种逻辑放入模板中。|offset|length|style|CODE|2359847|entityMap^0|0|11|E|1R|4|2V|4|0^^$0|@$1|2|3|4|5|6|7|J|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|K|8|@$D|L|E|M|F|G]|$D|N|E|O|F|G]|$D|P|E|Q|F|G]]|9|@]|A|$]]|$1|H|3|-4|5|6|7|R|8|@]|9|@]|A|$]]]|I|$]]

Like Ignacio Vazquez-Abrams pointed out in the first comment, that's not really a great way to code your logic. I would ensure that your variable has a certain type. That could be solved through an additional variable you add to the context or an object that holds the data and something that describes the type of data.

If you want to stick to your logic, a possible approach would be to write your own template filter (let's call it <code>date_or_string</code>). The filter could subclass the builtin <code>date</code> filter with the format parameter being optional. In case the parameter is passed it works like the normal <code>date</code> filter, without the parameter it simply returns the string. In a more complex scenario the filter could also do some type checking. Just an idea, i wouldn't actually put that kind of logic into the template.

blocks|key|2233881|text|您还可以实现一个与type()内置等效的通用模板筛选器：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|2233882|#+app/templatetags/util.py
from+django+import+template

register+=+template.Library()

@register.filter
def+get_type(value):
++++return+type(value)

#+template.html
{%25+load+util+%25}
{%25+if+extra_column%7Cget_type+==+'str'+%25}
++++String
{%25+elif+extra_column%7Cget_type+==+'datetime.date'+%25}
++++Date
{%25+else+%25}
++++Oh+no!
{%25+endif+%25}|code-block|syntax|javascript|2233883|然而，我认为Ignacio和Dirk是对的。您不能只有两个键(您说的是“数组”，但我假设您指的是“字典”，因为项有名称)，分别称为date和detail|2233884|#+views.py
...
actions+=+[{
++++'some_property':+'some_value'
++++'date':+None,
++++'detail':+'details'
},
{
++++'some_property':+'some_value'
++++'date':+datetime.date.today(),
++++'detail':+None
}]
...

#+template.html
{%25+for+action+in+actions+%25}
<td>{%25+if+action.date+%25}{{+action.date%7Cdate:"M+d"+}}{%25+endif+%25}{{+action.detail+}}</td>
{%25+endfor+%25}

#+output
<td>details</td>
<td>Aug+19</td>|2233885|entityMap^0|9|6|0|0|1T|4|1Y|6|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@$9|R|A|S|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|T|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|U|8|@$9|V|A|W|B|C]|$9|X|A|Y|B|C]]|D|@]|E|$]]|$1|M|3|N|5|H|7|Z|8|@]|D|@]|E|$I|J]]|$1|O|3|-4|5|6|7|10|8|@]|D|@]|E|$]]]|P|$]]

You could also implement a general template filter as an equivalent to the <code>type()</code> builtin:

<pre><code># app/templatetags/util.py
from django import template

register = template.Library()

@register.filter
def get_type(value):
 return type(value)

# template.html
{% load util %}
{% if extra_column|get_type == 'str' %}
 String
{% elif extra_column|get_type == 'datetime.date' %}
 Date
{% else %}
 Oh no!
{% endif %}
</code></pre>

I think Ignacio and Dirk are right, however. Can't you just have two keys (you say "array", but I assume you mean "dictionary" from the fact that the items have names) called <code>date</code> and <code>detail</code>?

<pre><code># views.py
...
actions = [{
 'some_property': 'some_value'
 'date': None,
 'detail': 'details'
},
{
 'some_property': 'some_value'
 'date': datetime.date.today(),
 'detail': None
}]
...

# template.html
{% for action in actions %}
&lt;td&gt;{% if action.date %}{{ action.date|date:"M d" }}{% endif %}{{ action.detail }}&lt;/td&gt;
{% endfor %}

# output
&lt;td&gt;details&lt;/td&gt;
&lt;td&gt;Aug 19&lt;/td&gt;
</code></pre>

blocks|key|2234805|text|我知道我在这方面落后了很多(落后了三年)，但我只是来到这里，希望做一些类似的事情，并提出我认为是一个像样的解决方案。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2234806|只需向get_model_type等模型添加一个函数，并让它返回您期望从每个模型返回的内容，如下所示：|offset|length|style|CODE|2234807|class+MyModelOne(models.Model):
++date_created+=+models.DateTimeField(auto_now_add=True)
++first_name+=+models.CharField(max_length=255)
++def+get_model_type(self):
++++return+"my_model_one"

class+MyModelTwo(models.Model):
++date_created+=+models.DateTimeField(auto_now_add=True)
++other_field+=+models.CharField(max_length=255)
++def+get_model_type(self):
++++return+"my_model_two"|code-block|syntax|javascript|2234808|然后，在您的模板中，您可以轻松地调用该函数：|2234809|{%25+if+model.get_model_type+==+'my_model_one'+%25}
++Model+One
{%25+elif+model.get_model_type+==+'my_model_two'+%25}
++Model+Two
{%25+endif+%25}|2234810|entityMap^0|0|3|E|0|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|T|8|@$D|U|E|V|F|G]]|9|@]|A|$]]|$1|H|3|I|5|J|7|W|8|@]|9|@]|A|$K|L]]|$1|M|3|N|5|6|7|X|8|@]|9|@]|A|$]]|$1|O|3|P|5|J|7|Y|8|@]|9|@]|A|$K|L]]|$1|Q|3|-4|5|6|7|Z|8|@]|9|@]|A|$]]]|R|$]]

I know I'm way behind on this (by three years) but I just got here looking to do something similar and came up with what I think is a decent solution.

Just add a function to your models like <code>get_model_type</code> and have it return something you'd expect from each model like so:

<pre><code>class MyModelOne(models.Model):
 date_created = models.DateTimeField(auto_now_add=True)
 first_name = models.CharField(max_length=255)
 def get_model_type(self):
 return "my_model_one"

class MyModelTwo(models.Model):
 date_created = models.DateTimeField(auto_now_add=True)
 other_field = models.CharField(max_length=255)
 def get_model_type(self):
 return "my_model_two"
</code></pre>

Then in your template you can easily just call that function:

<pre><code>{% if model.get_model_type == 'my_model_one' %}
 &lt;p&gt;Model One&lt;/p&gt;
{% elif model.get_model_type == 'my_model_two' %}
 &lt;p&gt;Model Two&lt;/p&gt;
{% endif %}
</code></pre>

blocks|key|2233922|text|派对来晚了，但我就是有个问题。我选择的解决方案是duck-typing，所以：|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|2233923|{%25+if+action.extra_column.year+%25}
++{{+action.extra_column%7Cdate:"M+y"+}}
{%25+else+%25}
++{{+action.extra_column+}}
{%25+endif+%25}|code-block|syntax|javascript|2233924|你能争辩说这绝对不是正确的方法吗？可能吧。它能在不编写模板过滤器和维护更多代码的情况下完成工作吗？绝对一点儿没错。|2233925|entityMap|0|LINK|mutability|MUTABLE|url|https://en.wikipedia.org/wiki/Duck_typing^0|O|B|0|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@$A|T|B|U|1|V]]|C|$]]|$1|D|3|E|5|F|7|W|8|@]|9|@]|C|$G|H]]|$1|I|3|J|5|6|7|X|8|@]|9|@]|C|$]]|$1|K|3|-4|5|6|7|Y|8|@]|9|@]|C|$]]]|L|$M|$5|N|O|P|C|$Q|R]]]]

Late to the party, but I just had this problem. The solution I went for is <a href="https://en.wikipedia.org/wiki/Duck_typing" rel="nofollow noreferrer">duck-typing</a>, so:
<pre><code>{% if action.extra_column.year %}
 {{ action.extra_column|date:&quot;M y&quot; }}
{% else %}
 {{ action.extra_column }}
{% endif %}
</code></pre>
Could you argue that this is definitely not the right way to do it? Probably. Will it get the job done without writing your own template filter and having even more code to maintain? Absolutely.

blocks|key|4086333|text|您可以尝试这样来识别字符串和列表类型：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4086334|{%25if+v_1.0.1%7Clength+==+0%25}
++++
++++{{v_1}}
{%25else%25}+++++
++++++++++++++++++++++++++++++++++++++++++++++++
++++{{v_1.0}}
{%25endif%25}|code-block|syntax|javascript|4086335|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

You can try this to recognize String vs List type:
<pre><code>{%if v_1.0.1|length == 0%}
 &lt;!--STR--&gt;
 {{v_1}}
{%else%} 
 &lt;!--List--&gt; 
 {{v_1.0}}
{%endif%}
</code></pre>

I have a variable that I'm pulling into a table that sometimes is a date and sometimes is a string. If the variable is a date, I want to change the formatting:

<pre><code>&lt;td&gt;{{ action.extra_column|date:"M d" }}&lt;/td&gt;
</code></pre>

But if it is a string, I just want to display it as is:

<pre><code>&lt;td&gt;{{ action.extra_column }}&lt;/td&gt;
</code></pre>

If I try to format it and it is a string, I get no output for the variable.

How can I determine the type so that I can adjust my rendering based on type.

Determine variable type within django template

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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我有一个变量，我把它放到一个表中，这个表有时是日期，有时是字符串。如果变量是日期，我想要更改格式：<td>{{ action.extra_column|date:"M d" }}</td>但是如果它是一个字符串，我只想按原样显示它：<td>{{ action.extra_column }}</td>如果我试图格式化它，...

问确定django模板中的变量类型
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