Indexing 2d arrays/lists

Question

Hi I am trying to find the index of a 2d array, but have only been able to find how to index each row at a time. Unfortunately this isn't useful as I cannot find the index for the other after the first indexing statement couldn't find the word in the list.

Here is the code I was attempting to use:

if not button:#code to be ran if in test screen
    #print("Test Mode")
    time.sleep(0.4)
    Wordtotranslate = self.driver.find_element_by_xpath('/html/body/div[4]/div[3]/div/div/div[1]/div[1]/div/div')
    Wordtotranslate = Wordtotranslate.text
    print(Wordtotranslate)
    def in_list():
        for i, sublist in enumerate(words_list2d):
            if Wordtotranslate in sublist:
                return i
        return -1
    in_list()

The error I get is:

Eng_Index = words_list2d[0].index(Wordtotranslate)

ValueError: 'on' is not in list

In short im looking to find the postion of an element(string) in a 2d array/list in python

Any help will be greatly appreciated

Answer 1

Here's an example of traversing a 2-dimensional array and extracting the index values for elements that match a criteria.

A couple notes:

• I used arbitrary example data since you didn't include specifics about the values you're dealing with
• I demonstrated handling duplicate values in the 2-dimensional array. Depending on your assumptions, you may need to adjust the logic (eg handling duplicates in words_to translate , maybe you used list.index() because only care about the first instance, etc.)

import collections

words_list2d = [
    ['here', 'are', 'example'],
    ['words', 'in', 'a'],
    ['2d', 'array', 'with'],
    ['duplicate', 'words', 'duplicate'],
]

words_to_translate = ['example', 'array', 'duplicate', 'words']

word_indexes = collections.defaultdict(list)

for row_index, row in enumerate(words_list2d):
    for value_index, value in enumerate(row):
        for word in words_to_translate:
            if word == value:
                word_indexes[word].append((row_index, value_index))
                break

for word in word_indexes:
    print(f"{word}: {word_indexes[word]}")

Output:

$ python3 find_words_in_2d_array.py
example: [(0, 2)]
words: [(1, 0), (3, 1)]
array: [(2, 1)]
duplicate: [(3, 0), (3, 2)]