InlineModelAdmin.get_max_num(request, obj=None, **kwargs)
Returns the maximum number of extra inline forms to use. By default, returns the InlineModelAdmin.max_num attribute.
Override this method to programmatically determine the maximum number of inline forms. For example, this may be based on the model instance (passed as the keyword argument obj):
class BinaryTreeAdmin(admin.TabularInline):
model = BinaryTree
def get_max_num(self, request, obj=None, **kwargs):
max_num = 1