天道酬勤,学无止境

list

Python rearrange list starting from a certain element

I have a python list and an index of an item I want to start a loop on the list starting from the element after my index. For example I have: original_list = [1,2,3,4,5] my_index = 2 new_list = [4,5,1,2,3] I am trying to achieve the new list.

2022-01-17 08:50:53    分类:问答    python   list

Some strange behavior Python list and dict

Can anyone explain why this happened with list and how to clean list after appending to another list? >>> t = {} >>> t["m"] = [] >>> t {'m': []} >>> t["m"].append('qweasdasd aweter') >>> t["m"].append('asdasdaf ghghdhj') >>> t {'m': ['qweasdasd aweter', 'asdasdaf ghghdhj']} >>> r = [] >>> r.append(t) >>> r [{'m': ['qweasdasd aweter', 'asdasdaf ghghdhj']}] >>> t["m"] = [] >>> r [{'m': []}]

2022-01-17 08:26:21    分类:问答    python   list   dictionary

Does the List in .NET work the same way as arraylist in Java?

When I learned Java, I was told that the arraylist works this way: It creates an array with room for 10 elements. When the 11th element is added, it is created a new list with room for 20 elements, and the 10 elements are copied into the new array. This will repeat as until there are no more elements to add, or to a maximum size. Is the List in .NET constructed the same way?

2022-01-17 08:08:11    分类:问答    java   .net   list   arraylist

Merging lists of lists

I have two lists of lists that have equivalent numbers of items. The two lists look like this: L1 = [[1, 2], [3, 4], [5, 6, 7]] L2 =[[a, b], [c, d], [e, f, g]] I am looking to create one list that looks like this: Lmerge = [[[a, 1], [b,2]], [[c,3], [d,4]], [[e,5], [f,6], [g,7]]] I was attempting to use map() : map(list.__add__, L1, L2) but the output produces a flat list. What is the best way to combine two lists of lists? Thanks in advance.

2022-01-17 08:00:09    分类:问答    python   list   merge

Is list[i] an alias for list.get_item(i) in C#?

I'm passing a lambda expression as a parameter. In this case, someObject has a property called property accessible with someObject.property. When I pass: o => o.childListOfObjects[0].property, where childListOfObjects is a List<someObejct> and , expression.Body returns o => o.childListOfObjects.get_Item(0).property. Skip to the end: Is list[i] an alias for list.get_item(i) in C#?

2022-01-17 07:32:08    分类:问答    c#   list   lambda   alias

Find Duplicate in list but with criteria

Want to remove duplicates from a list so if my list contains: www.test.com test.com mytest.com I want the final list to look like below(only selecting the domains with www from the duplicate in front) : www.test.com mytest.com I have this linq but it seems to ignore all the domains which dont have www in front because it is selecting only www ones: var result=inputList.Where(x=>x.DomainName.StartsWith("www.")).Distinct(); Edit: @DanielHilgarth: I just run your code and it doesnt produce right results. I have : test.com www.test.com test2.com www.test2.com test3.com www.test3.com test4.com in

2022-01-17 07:12:42    分类:问答    c#   linq   list

How to iterate over list while removing items at the same time?

I'm trying to find an elegant way to iterate over a list while items are removed at the same time.I know this solution. But my conditions are something harder: all single-threaded here Iteration must be forward. Every item must be processed exactly once. Multiple and random items can be removed while 1 item is being processed. Items are complex and smart objects. They execute a custom method and it can decide that some items (0 to all) shall be removed. (add and insert can happen too, but just now this is not important, in case there is a way to handle this at the same time, that would be

2022-01-17 07:01:14    分类:问答    c#   list   iteration

Extracting boundaries of dense regions of 1s in a huge list of 1s and 0s

I'm not sure how to word my problem. But here it is... I have a huge list of 1s and 0s [Total length = 53820]. Example of how the list looks like - [0,1,1,1,1,1,1,1,1,0,0,0,1,1,0,0,0,0,0,0,1,1...........] The visualization is given below. x-axis: index of the element (from 0 to 53820) y-axis: value at that index (i.e. 1 or 0) Input Plot--> The plot clearly shows 3 dense areas where the occurrence of 1s is more. I have drawn on top of the plot to show the visually dense areas. (ugly black lines on the plot). I want to know the index numbers on the x-axis of the dense areas (start and end

2022-01-17 07:00:28    分类:问答    python   python-3.x   list   kernel-density

What type are Lists of any type in Perl 6?

Consider the following Python code (as an example): a = 5 b = "a" l = [a, b] # -> typing.List[typing.Any] print(l) # [5, "a"] The type of list l is list; it is not constrained by the types it holds because Python is quite dynamically typed. Contrast this with, say, Go, which is strongly structurally typed: var list []uint8{1, 2, 3, 4, 5, 6} That list can only hold unsigned integers up to 255. It cannot hold any other type. Also Go: var multi interface{"string", []int{9, 5}, rune('5'), []interface{}} Interfaces allow for containers of variant types. Consider Perl 6, which is even more

2022-01-17 06:40:41    分类:问答    list   raku

Convert Pandas data frame to a list of tuples containing IDs and a weight

I have a data frame (called df) which is currently formatted like so: 1 2 3 1 1 0.26 0.02 2 0.26 1 0.61 3 0.02 0.61 1 The IDs are connected by a value and I would like to somehow extract all unique ID values in order to have a more efficient way to add them to my graph on networkx. The output should look like something like this: ed_list = [(1,2,{'weight': 0.26}),(1,3,{'weight': 0.02}),(2,3,{'weight':0.61})] At the moment I use the following method: # Create matrix new_ = df.values A_d = np.matrix(new_) G = nx.from_numpy_matrix(A_d) I'm wondering if it would be easier/more efficient to create

2022-01-17 06:24:26    分类:问答    python-3.x   pandas   list   tuples   networkx