CODEWITHSUNDEEP
python
Duck.Jpeg
Duck.Jpeg

Reputation: 1

choosing 5 random numbers / coordinates on a grid in python

I need help with making this so I can convert a string into a number in a list, I have done this but if I wanted to do it this way I would have to wright a dictionary with 100 definitions which I do not want to do. The code is just to show what I found all ready. As you can see this would take 100 definitions if I were to do it this way.

x1 = [0,0,0,0,0,0,0,0,0,0]
x2 = [0,0,0,0,0,0,0,0,0,0]
x3 = [0,0,0,0,0,0,0,0,0,0]
x4 = [0,0,0,0,0,0,0,0,0,0]
x5 = [0,0,0,0,0,0,0,0,0,0]
x6 = [0,0,0,0,0,0,0,0,0,0]
x7 = [0,0,0,0,0,0,0,0,0,0]
x8 = [0,0,0,0,0,0,0,0,0,0]
x9 = [0,0,0,0,0,0,0,0,0,0]
x10 = [0,0,0,0,0,0,0,0,0,0]

my_dict_grid = {
  'x2[3]' : x2[3]
}

x = 'x2[3]'

print(my_dict_grid[x])

Upvotes: 0

Views: 384

Answers (3)

André
André

Reputation: 1068

A more mathematical, but very practical way to do this with numpy:

import numpy as np
grid_shape = [10, 10] # define 10 x 10 grid
num_ones = 5
cells = np.zeros(grid_shape[0]*grid_shape[1]) # define 10*10 = 100 cells as flat array
cells[0:num_ones] = 1 # Set the first 5 entries to 1
np.random.shuffle(cells) # Shuffle the entries, such that the 1's are at random position
grid = cells.reshape(grid_shape) # shape the grid into the desired shape

Running the code above and will e.g. result in grid=

[[0. 0. 1. 0. 0. 0. 0. 0. 0. 0.]
 [0. 0. 0. 0. 0. 0. 0. 0. 0. 0.]
 [0. 0. 0. 0. 0. 0. 0. 0. 0. 0.]
 [0. 0. 0. 0. 0. 0. 0. 0. 0. 0.]
 [0. 0. 1. 0. 0. 0. 0. 0. 0. 0.]
 [0. 0. 0. 0. 0. 0. 0. 0. 0. 0.]
 [0. 0. 0. 0. 0. 0. 0. 1. 0. 0.]
 [0. 0. 0. 0. 1. 0. 0. 0. 0. 0.]
 [0. 0. 0. 0. 0. 0. 0. 0. 0. 0.]
 [0. 1. 0. 0. 0. 0. 0. 0. 0. 0.]]

Note that, by changing grid_shape you can resize your grid, and by changing num_ones, you will adapt the number of ones in your grid. Also, it is guaranteed that there will always be num_ones ones in your grid (given that num_ones is smaller or equal the number of elements in the grid).

Upvotes: 0

tituszban
tituszban

Reputation: 5152

If you have multiple arrays you are managing all at once, create a multi-dimensional array:

x = [
    [0,0,0,0,0,0,0,0,0,0],
    [0,0,0,0,0,0,0,0,0,0],
    [0,0,0,0,0,0,0,0,0,0],
    [0,0,0,0,0,0,0,0,0,0],
    [0,0,0,0,0,0,0,0,0,0],
    [0,0,0,0,0,0,0,0,0,0],
    [0,0,0,0,0,0,0,0,0,0],
    [0,0,0,0,0,0,0,0,0,0],
    [0,0,0,0,0,0,0,0,0,0],
    [0,0,0,0,0,0,0,0,0,0]
]

In that case, you can just index by row then column:

x[2][3]

Based on your comment, you want to randomly change values in the array. In that case, the approach above is not at all what you want. You want to pick two random numbers, and index to them in x to change them:

import random

for _ in range(5):
    updated = False
    while not updated:
        i = random.randrange(10)
        j = random.randrange(10)
        if x[i][j] == 0:
            x[i][j] = 1
            updated = True

Original answer to the initial question:

(this is here more as an interesting thing, not as a viable approach)

Okay. Assuming that you have to do it the way you have described, you can generate a dictionary with all of the string keys:

my_dict_grid = {
   f"x{i + 1}[{j}]": arr[j]
   for i, arr in enumerate([x1, x2, x3, x4, x5, x6, x7, x8, x9, x10])
   for j in range(10)
}

However, I have to stress that this is not a good idea.

Upvotes: 2

Sefan
Sefan

Reputation: 709

3 different ways to solve this with oneliners, depending of the output you want:

my_list = [[ 0 for _ in range(10)] for _ in range(10)]
my_dict = {"x"+str(i+1):[ 0 for _ in range(10)] for i in range(10)}
my_dict2 = {"x"+str((i+1)%10)+"["+str(int((i+1)/10))+"]": 0 for i in range(100)}
print(my_list) #[[0, 0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0,...
print(my_dict) #{'x10': [0, 0, 0, 0, 0, 0, 0, 0, 0, 0], 'x9': [0,...
print(my_dict2)#{'x4[3]': 0, 'x1[9]': 0, 'x6[6]': 0, 'x2[8]': 0,...

Upvotes: 1

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