问题
I need to combine a string along with a list of strings into a tuple so I can use it as a dictionary key. This is going to be in an inner loop so speed is important.
The list will be small (usually 1, but occasionally 2 or 3 items).
What is the fastest way to do this?
Before:
my_string == "foo"
my_list == ["bar", "baz", "qux", "etc"]
After:
my_tuple == ("foo", "bar", "baz", "qux", "etc")
(Note: my_list must not be altered itself).
回答1:
I can't speak for performance, but this is definitely the simplest I can think of:
my_tuple = tuple([my_string] + my_list)
回答2:
The straightforward way is simply my_tuple = tuple( my_list + [my_string] ). I would certainly start with that and see if the performance is acceptable before trying to figure out any crazy ways of subverting the normal system for speed.
回答3:
i think this way is better:
my_list = my_list.insert(0,my_string)
my_tuple = tuple(my_list)
来源：https://stackoverflow.com/questions/5453979/create-a-tuple-from-a-string-and-a-list-of-strings