python - python len() throwing operator expected in django binding

Question

I'm new to Python and Django, and have the following line of code in an html template:

{% if len(dato.titulo) > 35 %} {{dato.titulo[:35] + '...'}} {% else %} {{ dato.titulo }}{% endif %}

the {% if len(dato.titulo) > 35 %} bit throws the exception. I tried using a truncatechars filter but the django version installed is apparently old and doesn't have the filter. How could I make this work (truncate the string if it has more than 35 characters)?

Answer 1

在 django 模板中使用|length过滤器来获取字符串的长度，因此将您的行更新为

{% if dato.titulo|length > 35 %} {{dato.titulo[:35] + '...'}} {% else %} {{ dato.titulo }}{% endif %}

看来您想截断字符串，在这种情况下您可以使用|truncatechars过滤器。因此无需检查长度并手动截断字符串。做就是了

{{ dato.titulo|truncatechars:35 }}

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如果不可truncatechars用，请|slice按照@Leonardo.Z所述使用，它将截断字符串，但不会...在末尾添加。

{{ dato.titulo|slice:35 }}

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或者编写您自己的模板过滤器来执行此操作。