Python-Value from list as a argument of other list

Question

I have a problem with lists because I want to get value from the list named test_table with value from A_table as an argument. Is there any way to get the proper result? Of course the lists aren't empty and when I run it I get Process finished with exit code -1073740791 (0xC0000409)

            for x in range(len(A_table)):
                print(test_table[A_table[x]])

Edit: List_A is generated like this: (i think that the problem is type-string not integer, but with int type my function doesn't work):

        A_letter = [find_all(sentence, 'A')]  
        A_string = ' '.join(map(str, A_letter[0]))
        data = A_string.split()  # split string into a list

        for temp in data:
            A_table.append(temp)

score 0 · Answer 1 · answered Apr 14 '20 at 10:13

Is this what you are trying to do? This code looks into test_list and if the value is found, prints it by calling the list.index() function.

list_a =[1,2,3,4]
test_list = [3,5,8,9]

for i in range(len(list_a)):
  if list_a[i] in test_list:
    print(test_list[test_list.index(list_a[i])])
//output = 3

Mitchell Tracy · Answer 2 · 2020-04-14T13:42:40.547

To start, I don't know where that find_all function is defined, but if it behaves like re.findall (which you should probably use), then it returns a list already, so by defining A_letter = [find_all(sentence, 'A')], you have a list of list of matches.

Consider this example:

>>> import re
>>> sentence = 'A wonderful sample of A test string'
>>> re.findall('A', sentence)
['A', 'A']

Moving on, your A_table has a list of str. So there is no direct way to index into another list using the values inside of A_table. For example, even if test_table has the values ['A', 'B', 'C'], the valid index values are still "0", "1", and "2", i.e. I cannot get test_table['A'], because lists may only be indexed by int.

If you want to get the index of a certain value (e.g. "A") in a list, you can use the index function of list, which returns the first index of the provided value, or raises a ValueError if the value is not found.

For example:

>>> import re
>>> 
>>> test_table=['Q','F','R','A','B','X']
>>> 
>>> sentence = 'A wonderful sample of A test string'
>>> A_table = re.findall('A', sentence)
>>> 
>>> for match in A_table:
...     # first check to ensure the match is in the test_table
...     if match in test_table:
...         # ok, I know it is here, so get the index
...         i = test_table.index(match)
...         v = test_table[i]
...         print(f'index [{i}] has value [{v}]')
... 
index [3] has value [A]
index [3] has value [A]

Edit: Here is some more info on the .index function, and here is another link to a question that indicates your present error is related to memory corruption.

Python-Value from list as a argument of other list

2 Answers2