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Check If a Field Has Changed

Author:
zmsmith
Posted:
May 26, 2010
Language:
Python
Version:
1.2
Score:
3 (after 3 ratings)

Used to check if a field of an object has changed.

This is probably most useful in the save method.

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def has_changed(instance, field):
    if not instance.pk:
        return False
    old_value = instance.__class__._default_manager.filter(pk=instance.pk).values(field).get()[field]
    return not getattr(instance, field) == old_value

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Comments

albertmenglongli (on November 15, 2017):

Seems that this snippet cannot handle Field like MultiSelectField well.

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