I would like to check all list values in a list and change them if necessary.
p.e.
I want to check the next lists if there are values higher or lower then the next values:
min-value = 6
max-value = 22
mylist = ['4-8','25','16-19','21-32']
if one of the list values is below the min-value or higher then the max-value, the list values must be changed to the min-value and max-value. p.e. in example, the new list must be:
mylist = ['6-8','22','16-19','21-22']
if the entire value of the list item is below the min-value or higher then the max-value the list item can be removed.
How can I check my list values and change them?
There are two approaches. In the procedural one, you iterate over the list items and modify or skip the element:
let newlist = []
for element in mylist
" Parse element.
if ! OutsideBounds(element)
call add(newlist, AdjustBounds(element))
endif
endfor
In the functional programming approach, you use the built-in map() to modify elements (i.e. adjust the bounds), but that one cannot remove elements. So just empty those elements and then do a second pass with filter() to remove them. Note that both functions modify the original lists, so use copy() if you need to keep the original.
call filter(map(mylist, 'AdjustBounds(v:val)'), '! OutsideBounds(v:val)')
I hope I don't need to tell you how to write the AdjustBounds() and OutsideBounds() functions...
Related
Number,IceCream
1,Chocolate
2,Vanilla
3,Mixed
Say if I
Number = input("Flavor?:")
I know that I need to index [0] because the numbers are on the first column. I also know that I will need to use .split(",") to remove the commas and to create a list.
Some assistance would be greatly appreciated!
It's confusing whether you plan to include integers in the list with the strings or not
Method 1: including integers with strings(flavor), create a list of tuples
icecream=[(1,'choc'),(2,'mix'),(3,'blueberry')]
print(icecream[0][1])
print(icecream[2][1])
Note: tuples are immutable
Method 2: I believe the best way to do this would be to use a dictionary instead of list. As dictionary has (Key, value) pairs, you could assign key(integer) to values(flavor), which then would make it easy accessing items just by keys(integers in your case) ex.
Ice_cream_flavors={1:"chocolate", 2:"vanilla", 3:"mixed"} #dictionary
to access values, you could use methods available in dictionary use get(), items()
Note: items() returns a tuple for each key,value pair.
ex.
Ice_cream_flavors={1:"chocolate", 2:"vanilla", 3:"mixed"}
new=Ice_cream_flavors.items()
for k,v in new:
if input==k:
print(v)
I have a list of unknown length containing strings. I want to compare the last item with the second to last item, but I can't find an easy way to retrieve these elements so I can compare them.
I tried getting the length of the list and then using (length-1) as the index I pass into the list GET function, but this doesn't seem to work.
set(my_list a b c) # I don't actually know the length of the original list
list(LENGTH my_list list_len)
list(GET my_list (list_len-1) last_item) # doesn't work
I expect to have element c saved in the last_item variable, but it remains empty. What is the right way to do this in CMake?
You have to use math in order to perform mathematical operations.
list(LENGTH my_list list_len)
math(EXPR list_last "${list_len} - 1")
list(GET my_list ${list_last} last_item)
Edit: It is possible to get elements from the end of a list using negative numbers, you can use -1 to get the last item of a list:
list(GET my_list -1 last_item)
How do I delete the content of a list in Netlogo?
This is a tuned-down version of my code to function as an example:
to calculate_SN
ask turtles [
set subjective_norm_list []
set subjective_norm_list [1 2 3 4 5]
set subjective_norm ( sum subjective_norm_list / length subjective_norm_list)
*delete content of subjective_norm_list so that it is empty again*
end
The part between asterisks I don't know.
Based on your shared code so far, you should take a different approach: create a function.
to-report subjective-norm [#lst]
report (sum #lst) / (length #lst)
end
It is unclear that you will ever need to assign a variable name to your list. You may be able to use it upon creation and then forget about it. (It will be garbage collected.)
If you want subjective_norm_list to be an empty list, you can set it to an empty list, just like you did when you initialized it the first time around:
set subjective_norm_list []
Note that, technically, NetLogo lists are immutable, so you're not deleting the elements in the list: you're just creating a new list with no elements in it and assigning it to the same variable. But for all intents and purposes, it's the same: subjective_norm_list is empty again.
I thought that [] and list() were two equal ways to create a list. But if you want a list with dictionnary keys,
var = [a_dict.keys()]
doesn't work since type(var) is [dict_keys], correct syntax is :
var = list(a_dict.keys())
I couldn't find an good explanation on this behaviour. Do you have one ?
TL;DR:
list() is the same as []
list(obj) is not the same as [obj]
a_dict.keys() is a dictionary view object, it returns an object which can be iterated to yield the keys of a_dict. So this line:
[a_dict.keys()]
is saying in python "I'm making a list with one element in it" and that one element is the dict keys iterator. It's a list literal in the syntax.
Now this line:
list(a_dict.keys())
is a call to the list builtin function. This function list attempts to iterate the argument and produce a list. It's a function call in the grammar.
The equivalent list literal (actually list comprehension) would be instead:
[key for key in a_dict.keys()]
Finally, note that dictionary objects iterate by keys anyway,
list(a_dict.keys()) would usually be written more simply as as list(a_dict) instead.
Hope this helps.
[a_dict.keys()]
This one puts a single element in the list. Just as if you were to write [1]. In this case that one element is going to be a list.
list(a_dict.keys())
The constructor accepts a sequence and will add all elements of the sequence to the container.
In my program my P = [0,1,2] I want to store it into another LIST, because P will keep changing in a loop so I want to store P into a LIST, so my LIST will be like below :
eg.
LIST = [[0,1,2],[3,4,5],[6,7,8]]
create_list([],[]).
create_list(G, [H|G]).
This is what I did, create_list(P,LIST). I not sure how to do it as it keep return me no. But I am pretty sure I can get different P because I am able to print them out each time P changed.
You need to create a predicate that receives the item (list in this case) you want to append to another input list, and this would give you a new list with the which has all the items of your input list plus the new item.
So, it would be something like:
create_list(Item, List, [Item|List]).
Initially the input List would be an empty list ([]), so you might call it
create_list([0,1,2], [], List1),
create_list([3,4,5], List1, List2),
create_list([6,7,8], List2, List).
This will result in List instantiated with [[0,1,2],[3,4,5],[6,7,8]]