Get Excel columns in list (Python or Javascript)-CodePudding

I am trying to get a list/array of the columns of an Excel spreadsheet, from A until ZZ.

["A","B","C", ... , "ZX","ZY","ZZ"]

What I have tried so far:

(Javascript)

const alphabetList = "ABCDEFGHIJKLMNOPQRSTUVWXYZ".split('');
const alphabetListCopy = "ABCDEFGHIJKLMNOPQRSTUVWXYZ".split('');

for (var i=0; i < alphabetListCopy.length; i  ){
  for (var j=0; i < alphabetListCopy.length; j  ){
    alphabetList.push(alphabetList[i][j]);
  }
}

console.log(alphabetList);

and this returns Error: Invalid array length

(I did the loop with alphabetListCopy to avoid this error https://forum.freecodecamp.org/t/push-new-element-into-array-using-for-loop/225401#:~:text=Your code crashed,push an element.)

In python I tried:

alphabet = "A-B-C-D-E-F-G-H-I-J-K-L-M-N-O-P-Q-R-S-T-U-V-W-X-Y-Z".split("-")

for letter in alphabet:
    for a in alphabet:
        alphabet.append(letter   a)
        
print(alphabet)

and this returns a MemoryError (I assumed it created an infinite loop)

CodePudding user response：

The code you are providing is making an infinite loop because you are appending values to an array and you are trying to add a value to a 2-dimension array while alphabetList is a 1-dimansion.

If you want to have a list of the values from A to ZZ in Javascript you can do this instead :

const alphabetList = "ABCDEFGHIJKLMNOPQRSTUVWXYZ".split('');

// here we do not want to make it const since we are populating it
let alphabetListCopy = "ABCDEFGHIJKLMNOPQRSTUVWXYZ".split('');
for(i = 0; i < alphabetList.length; i  ) {
    for(j = 0; j < alphabetList.length; j  ) {
        alphabetListCopy.push(`${alphabetList[i]}${alphabetList[j]}`) // we add to the array the new value
    }
}

CodePudding user response：

For an easy approach to get the alphabet:

alphabet = [chr(i) for i in range(65, 91)]

To get all combinations, itertools has a nice collection of tools:

import itertools
alpha_combi = [''.join(subset) for subset in itertools.combinations_with_replacement(alphabet, 2)]
alphabet  = alpha_combi

where each subset is a tuple of two letters.

CodePudding user response：

Code:

import string
alphabet = list(string.ascii_uppercase)

new= []
for alpha in alphabet:
    for a in range(len(alphabet)):
        new.append(alpha alphabet[a])
    
len(alphabet new)

ternary:

alphabet [alphabet[a] alpha for a in range(len(alphabet)) for alpha in alphabet]

New list length 702