A bunch of commonly performed tasks that can be done quite tersely. Not always the best to use these for readability concerns but fun to take a look at or thing I have to look up.
Many of these examples make use of the itertools and functools built-in modules. I use some default naming such as
L for list,
D for dictionary.
Creating a new dictonary:
Updating an existing dictionary:
Which one to use depends on your usecase.
Counting values in an iterable
Counting values of a certain type in ant iterable can be done in many ways, here are a few.
sum(value == "target" for value in L)
Or alternatively you could use:
sum(1 for value in L if value == "target")
Or use the builtin
import collections collections.Counter(L)["target"]
Using a normal for loop and a collector variable is of course also possible!