CODEWITHSUNDEEP
javapython
Narendra Modi
Narendra Modi

Reputation: 861

Creating a list of arrays

I am having a data in the form of ids and value , where the value of ids are not continuous , i want to store the data in arraylist.

For Java: 

ArrayList<Integer>[] Data = new ArrayList[1000000];
for(int i=0;i<Data.length;i++) Data[i] = new ArrayList<>();

for(int i=0;i<n;i++){
    int id_index = in.nextInt();
    int value = in.nextInt();
    Data[id_index].add(value);
}

How to implement the same functionality in Python ?

Upvotes: 0

Views: 58

Answers (3)

pd shah
pd shah

Reputation: 1406

I think different way. python is a dynamic type language. dose not need to define variables like java.

just append every things u like, by every size you want!

>>> x=[]
>>> x.append([12])
>>> x
[[12]]
>>> x.append([15,16,17])
>>> x
[[12], [15, 16, 17]]

Upvotes: 0

Mohd
Mohd

Reputation: 5613

As Alex Hall's answer stated, you can use a list of lists as the following:

data = [[] for i in range(1000000)]

I just want to add the second part of your code:

for _ in range(n):
    id_index, value = raw_input().split()
    data[int(id_index)].append(int(value))

If you are using python 3.x then change raw_input() to input()

Upvotes: 0

Alex Hall
Alex Hall

Reputation: 36043

A list of lists will do fine, which can be created as so:

data = [[] for i in range(1000000)]

Upvotes: 1

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