Python Extracts Indexes That Match Two-Dimensional List Conditions

I would like to extract an index of a list containing two or more specific elements.

Specifically

 li = [[1, 2, 3], [2, 3, 4], [3, 4, 5], [4, 5, 6], [2, 3, 4], [1, 2, 3], [2, 3, 4], [5, 6, 7]]

Indexing lists containing 2 and 3 from

list=[0,1,4,5,6]

I would like to create a list that will be .
Thank you for your cooperation.

python

2022-09-30 20:14

4 Answers

You can extract it in one line by combining the list inclusion with enumerate, set type.

 li = [[1, 2, 3], [2, 3, 4], [3, 4, 5], [4, 5, 6], [2, 3, 4], [1, 2, 3], [2, 3, 4], [5, 6, 7]]
list = [i for i, lin enumerate(li) if set([2,3]).issubset(l)]
list
# [0, 1, 4, 5, 6]

2022-09-30 20:14

You can use the following code.

 li = [[1, 2, 3], [2, 3, 4], [3, 4, 5], [4, 5, 6], [2, 3, 4], [1, 2, 3], [2, 3, 4], [5, 6, 7]]

    newList = [ ]
    
    for index, innerList in enumerate(li):
        if2 in innerList and 3 in innerList:
            newList.append(index)
            
    print(newList)
    # Output [0, 1, 4, 5, 6]

First, create an empty list newList=[] with the new index.
In enumerate(li), extract the list (innerList) and index number in the list and turn the for statement.

Check if2innerList to see if2innerList in the list and 3innerList to see if3innerList in the list.

If both are included, add the index number to the newList.

2022-09-30 20:14

Using numpy to set the variable li to the numpy.ndarray type makes it a little easier.

>>import numpy as np
>>li=np.array([
  [1, 2, 3], [2, 3, 4], [3, 4, 5], [4, 5, 6],
  [2, 3, 4], [1, 2, 3], [2, 3, 4], [5, 6, 7]
])
>>np.intersect 1d (*[np.where(li==k)[0]forkin(2,3)])
array([0,1,4,5,6])

2022-09-30 20:14

This method uses the Boolean operation of NumPy.You can look for any number of values.

import numpy as np

def search_index(li, values):
    arr=np.asarray(li)
    arr_v=np.asarray(values).reshape(-1,1,1)
    return(arr==arr_v).any(2).all(0).nonzero()[0]

Examples of operation:

In[11]: li = [[1, 2, 3], [2, 3, 4], [3, 4, 5], [4, 5, 6], [2, 3, 4], [1, 2, 3], [2, 3, 4], [5, 6, 7]]

In[12]—search_index(li, [2,3])
Out [12]—array([0,1,4,5,6], dtype=int64)

In[13]—search_index(li, [2,3,4])
Out [13]—array([1,4,6], dtype=int64)

In[14]: search_index(li, [1])
Out [14]—array ([0,5], dtype=int64)

2022-09-30 20:14

If you have any answers or tips

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