Python integer infinity for slicing

I have defined a slicing parameter in a config file:

max_items = 10

My class slices a list according to this parameter:

items=l[:config.max_itmes]

When max_items = 0, I want all items to be taken from l. The quick and dirty way is:

config.max_items=config.max_items if config.max_items>0 else 1e7

Assuming that there will be less then 1e7 items. However, I don't fancy using magic numbers. Is there a more Pythonic way of doing it, like an infinity integer constant?