How to format datetime in a Flask application?

Question

How can I make it show only dd/mm/yy and take the hours and seconds in my database or templates?

Database:

class User(db.Model):

    __tablename__ = 'users'

    id = db.Column(db.Integer, primary_key=True)
    first_name = db.Column(db.String(120))
    last_name = db.Column(db.String(120))
    callsing = db.Column(db.String(10), unique=True)
    username = db.Column(db.String(120))
    ifc = db.Column(db.String(64)) 
    password = db.Column(db.String(120))
    email = db.Column(db.String(120), unique=True)  
    age = db.Column(db.String(5))
    grau = db.Column(db.String)
    about_me = db.Column(db.Text(140))
    last_seen = db.Column(db.DateTime, default=datetime.utcnow)

Template:

{% for f in range(2) %}
    <tr>
       <td><img src="../static/img/arrow-gray.png" alt="">
           <font color="#006400">IFAB {{ form[f].callsing }} </font>
       </td>
       <td>{{ form[f].first_name  }} <b>{{ form[f].last_name }}</b></td>
       <td>{{ form[f].last_seen }}</td>
    </tr>
{% endfor %}

Answer 1

You can use the function strftime:

<td>{{ form[f].last_seen.strftime('%d/%m/%Y') }}</td>

Or create a specific filter for this.

app = ... # instância do Flask.

@app.app_template_filter('to_date')
def format_datetime(value):
    return value.strftime('%d/%m/%Y')

And then use in your template as:

<td>{{ form[f].last_seen|to_date }}</td>

It is worth remembering that in this second case it is possible to use <var>|to_date with any type of variable, so it might be interesting to do a treatment in function format_datetime to validate that the type of value received as argument datetime before trying to call the function strftime.