how to replace values in a 2D array with a text in python

Question

how to replace all values equal to 1 with letters from a text ?

And if the text doesn't fit entirely in the array, how to generate automatically new arrays identical to the first one to aim at containing all characters ?

Thanks in advance.

text = "helloworldddd"
my_array = [ [0,1,1],[1,1,0],[1,0,0] ]

result expecting: generated arrays which contains all characters
my_array2 = [ [0,h,e],[l,l,0],[o,0,0] ]
my_array3 = [ [0,w,o],[r,l,0],[d,0,0] ]
my_array4 = [ [0,d,d],[d,1,0],[1,0,0] ]

Answer 1

With lists and copying you should read about the difference of shallow and deepcopy, else you just copy the lists refs - not the values. Read more here: Deep copy a list in Python

Calculating how many repeats you need is easy, compute the number of 1s in the patters, divide length of string by that and add 1 for good measure (integer division is floor_division) if it would divide with rest (use mod to check that).

Deepcopy yourself a resultlist thats long enough and start replacing 1 by characters:

from itertools import chain  # chaining multiple lists together
import copy                  # deepcopying the array to decouple copies

def createArr(t:str,arr:list):
    """Puts each character of t on the 1s of arr, extends arr with itself as pattern"""

    ones = sum(1 if q==1 else 0 for n in arr for q in n) # how many 1 in pattern
    mult = len(t)//ones  # how many reps needed for our text?
    if len(t)%ones != 0:
        mult += 1

    # create sufficient space by deepcopying the pattern into a longer list
    rv = list(chain(*(copy.deepcopy(arr) for _ in range(mult))))

    # start in sublinst on index 0
    subidx = 0
    # replace the 1s
    for c in t:    # walk all characters
        # maybe advance sublist index - if no 1s left
        while 1 not in rv[subidx] and subidx<len(rv):
            subidx+=1
        sub = rv[subidx] # get sublist
        sub[sub.index(1)] = c  # replace first 1 with act. char

    return rv 


text = "helloworldddd"
my_array = [ [0,1,1],[1,1,0],[1,0,0] ]


print(createArr(text,my_array))

Output:

 [[0, 'h', 'e'], ['l', 'l', 0], ['o', 0, 0], 
  [0, 'w', 'o'], ['r', 'l', 0], ['d', 0, 0], 
  [0, 'd', 'd'], ['d', 1, 0],   [1, 0, 0]]

You could partition that if need be, using the length of arr into equal parts, this high ranked questions and it's answers tell you how: How do you split a list into evenly sized chunks?