It’s because any iterable can be joined (e.g, list, tuple, dict, set), but its contents and the “joiner” must be strings. For example: Using something other than strings will raise the following error:
It’s because any iterable can be joined (e.g, list, tuple, dict, set), but its contents and the “joiner” must be strings. For example: Using something other than strings will raise the following error:
Error messages usually mean precisely what they say. So they must be read very carefully. When you do that, you’ll see that this one is not actually complaining, as you seem to have assumed, about what sort of object your list contains, but rather about what sort of object it is. It’s not saying it wants your list to … Read more
If you only want one item’s count, use the count method: Important Note regarding count performance Don’t use this if you want to count multiple items. Calling count in a loop requires a separate pass over the list for every count call, which can be catastrophic for performance. If you want to count all items, or even just multiple items, use Counter, … Read more
The easiest way I can think of is to use Linq:
Clearest and fastest way to do it. You can also consider using a set, but constructing that set from your list may take more time than faster membership testing will save. The only way to be certain is to benchmark well. (this also depends on what operations you require)
First declare your list properly, separated by commas. You can get the unique values by converting the list to a set. If you use it further as a list, you should convert it back to a list by doing: Another possibility, probably faster would be to use a set from the beginning, instead of a … Read more
You can use the List.addAll() method. It accepts a Collection as an argument, and your set is a Collection. EDIT: as respond to the edit of the question.It is easy to see that if you want to have a Map with Lists as values, in order to have k different values, you need to create k different lists.Thus: You cannot avoid … Read more
use reversed() function: It’s much more meaningful. Update: If you want it to be a list (as btk pointed out): Update: If you want to use only range to achieve the same result, you can use all its parameters. range(start, stop, step) For example, to generate a list [5,4,3,2,1,0], you can use the following: It may be less intuitive but as … Read more
Use random.choice(): For cryptographically secure random choices (e.g., for generating a passphrase from a wordlist), use secrets.choice(): secrets is new in Python 3.6. On older versions of Python you can use the random.SystemRandom class: