Question

How to display a datetime object as a string format for printing?

Here is the string I am trying to print:

'Text %s, on date: %d' % (x.name, x.time)

And here is the error I am getting:

%d format: a number is required, not datetime.datetime

Answer 1

Solution

You need to change the type: in template or in argument:

'Text %s, on date: %s' % (x.name, x.time)

But datetime.datetime instance is just an object (it has some kind-of-human-friendly string representation). You can change that to be friendlier this way:

'Text %s, on date: %s' % (x.name, x.time.isoformat())

You can even format it using strftime():

'Text %s, on date: %s' % (x.name, x.time.strftime('%A, %B %d, %Y'))

Test

Lets test it:

>>> import datetime
>>> now = datetime.datetime.now()  # our "now" timestamp
>>> '%d' % now

Traceback (most recent call last):
  File "<pyshell#2>", line 1, in <module>
    '%d' % datetime.datetime.now()
TypeError: %d format: a number is required, not datetime.datetime
>>> '%s' % now.isoformat()
'2012-09-25T22:24:30.399000'
>>> now.strftime('%A, %B %d, %Y')
'Tuesday, September 25, 2012'

Alternative – .format()

String formatting operations (%) are one way of formatting string, but there is also another – preferred – way to format strings: .format() method.

The reason for that is a different topic, but I can show you how the above examples would look like using .format() method:

'Text {x.name}, on date: {x.time}'.format(x=x)  # accessing properties
'Text {0}, on date: {1}'.format(x.name, x.time)  # accessing by positions
'Text {}, on date: {}'.format(x.name, x.time)  # in Python >2.7 it can be shorter
'Text {0}, on date: {1}'.format(x.name, x.time.isoformat())  # ISO format
'Text {0}, on date: {1}'.format(x.name, x.time.strftime('%A, %B %d, %Y'))