The `max` function

Using the `max` function in python 3.6. Some caveats to watch out for.

Transcript

1. max() caveats to consider
2. Max function # Assume `L` is a list of datetimes, Nonetypes L = get_dates() max(L) # returns biggest item @eloy · python 3.6 · 2018 2/11
3. Original code component_times = max( rr_time, spo2_time, o2device_time, t_time, sbp_time, hr_time) @eloy · python 3.6 · 2018 3/11
4. Empty sequence # Can we get a max item from an empty sequence? max([]) @eloy · python 3.6 · 2018 4/11
5. Handle TypeError # Lets handle the `TypeError` try: max([]) except TypeError: pass # Lets write less and make it more readable max([], default=None) @eloy · python 3.6 · 2018 5/11
6. None list # Can we get a max item from a list of Nonetypes? L = [None, None] max(L) @eloy · python 3.6 · 2018 6/11
7. Handle ValueError # Lets handle the `ValueError` L = [None, None] try: max(L) except ValueError: pass # What if `L` had both datetimes and Nonetype values? L = L + get_dates() @eloy · python 3.6 · 2018 7/11
8. Remove None items # Remove Nonetypes before using Max max([i for i in L if is not None]) @eloy · python 3.6 · 2018 8/11
9. Does this work? # Remove Nonetypes before using Max L = [None, None, None] max([i for i in L if is not None]) @eloy · python 3.6 · 2018 9/11
10. With default param # Remove Nonetypes before using Max L = [None, None, None] max([i for i in L if is not None], default=None) @eloy · python 3.6 · 2018 10/11
11. Filter # Remove Nonetypes before using Max max(filter(None, L), default=None) @eloy · python 3.6 · 2018 11/11