Translate VBA array into Python

Question

USING IDLE/Python 3.5.1

May I first of all begin by saying I am a reasonably experienced programmer in VBA but am on day 2 of Python. I assure you I have conducted many searches on this question but the 30 or so documents I have read do not seem to explain my problem.

May I also please request that any answers given are properly formatted code for Python 3.5.1 rather than helpful pointers to other documentation or links?

The Problem

I am running a report and outputting results as I go. I need to store the results (presumably in an array) during this so that I can refer to them afterwards. The report (and the populating of the array) can be rerun multiple times so please bear that in mind if using concepts like 'append' when building the array. The array has dimensions [25,4] - a maximum of 25 records with four items in each.

Day   X  Y  Z  Total
1     2  3  4  9
2     3  4  5  12 ...

(Purists: The total needs to be recorded rather than calculated because of rounding.)

I could solve the problem myself if someone could translate this bit of code into Python (from VBA for illustration purposes). I do not want to import the arrays module unless it's the only way. Note: Variable l is a loop that makes the array get built twice to demonstrate that the array needs to be capable of rebuilding from scratch rather than being created just the once.

Sub sArray()
    Dim a(25, 4)
    For l = 1 To 2 
        For i = 1 To 25
            For j = 1 To 4
                a(i, j) = Int(100 * Rnd(1)) + 1
                Debug.Print a(i, j);
            Next j
        Next i
    Next l
End Sub

Thanks,

Tom

Answer 1

I am not sure I got your question correctly... If you want to make an array (list i a better term in this case) of size [25,4] this is one way to go:

import random
a = [[int(100*random.random())+1 for j in range(4)] for i in range(25)]

>>> print a
[[74, 17, 36, 75],
 [1, 79, 33, 90],
 [58, 66, 47, 95],
 [35, 40, 87, 38],
 [43, 46, 34, 66],
 [69, 34, 26, 49],
 [56, 83, 44, 14],
 [2, 44, 54, 97],
 [50, 21, 39, 60],
 [13, 94, 12, 48],
 [36, 13, 2, 71],
 [77, 44, 31, 11],
 [56, 26, 30, 39],
 [17, 13, 83, 84],
 [54, 37, 34, 18],
 [5, 54, 88, 100],
 [22, 77, 70, 21],
 [51, 88, 26, 97],
 [69, 33, 86, 48],
 [42, 66, 38, 78],
 [71, 43, 96, 23],
 [6, 46, 100, 29],
 [32, 86, 15, 48],
 [96, 84, 8, 56],
 [29, 64, 69, 79]]

if you want to show that "the array needs to be capable of rebuilding from scratch rather than being created just the once" (why would you need this??)

for l in range(2):
    a = [[int(100*random.random())+1 for j in range(4)] for i in range(25)]

Also, the way of generating random numbers is odd (I have translated you method). To get the same result in python, just use random.randint(1,100) to generate random integers from 1 (i think you do not want to have 0 there) to whatever number you like.

If I have correctly understood from your comments, this is what you want:

def report(g=25):
    array = []
    for _ in range(g):
        x = random.randint(1,10)
        y = random.randint(1,10)
        z = random.randint(1,10)
        total = x+y+x
        row = [x,y,z,total]
        print(row)
        array.append(row)
    return array

result = report()
#prints all the rows while computing

>>> result #stores the "array"
[8, 4, 3, 20]
[10, 7, 4, 27]
[2, 4, 5, 8]
[8, 5, 8, 21]
[9, 7, 2, 25]
[2, 2, 3, 6]
[5, 8, 6, 18]
[8, 6, 1, 22]
[7, 6, 4, 20]
[7, 2, 10, 16]
[6, 5, 9, 17]
[3, 8, 8, 14]
[9, 1, 9, 19]
[1, 7, 7, 9]
[6, 6, 2, 18]
[9, 10, 1, 28]
[4, 6, 2, 14]
[6, 1, 6, 13]
[4, 1, 3, 9]
[5, 3, 5, 13]
[7, 5, 2, 19]
[9, 5, 7, 23]
[2, 5, 8, 9]
[3, 10, 4, 16]
[5, 6, 5, 16]