Printing Coordinates to a csv File

Question

I would like to extract coordinates to a .csv file with the brackets and comma delimiter format (x,y).

I have a 4x4 matrix written as a list (network1) and need to identify the coordinates where a 1 occurs to then export these coordinates to a .csv file.

The code below was suggested by another user which works great for a different set of data, although I need to adjust this a bit further to suit this format.

I expect there is only a small modification needed in the existing code which is below.

import numpy as np
import pandas as pd

network1 = [0,1,0,0,0,0,1,0,0,0,1,1,0,0,1,1]
network1_matrix = np.array(network1).reshape(4, 4)

coordinates = np.transpose(np.where(network1_matrix == 1))

result_df = pd.DataFrame({'1': coordinates[:, 0] + 1, '2': coordinates[:, 1] + 1})
result_df = result_df.append({'1': ';', '2': ''}, ignore_index=True)
result_df.columns = ['set A :=', '']

result_df.to_csv('result.csv', sep=' ', index=False)

This produces an output as follows (I have included results from a text file for greater clarity):

For this specific output, I need it in the following format:

I would greatly appreciate the assistance to complete the following as per the second image:

1. Print set A := to the .csv file without the quotation marks (" ") around it.
2. Print the coordinates with the brackets and only delimited by a comma.

Thanks a lot for the help!

Answer 1

I have seen your problem. Now fix this issue..

df.to_csv(quotechar='"')
      

bydefault quotechar is string. Think about it.

So try this like...

import numpy as np
import pandas as pd

network1 = [0,1,0,0,0,0,1,0,0,0,1,1,0,0,1,1]
network1_matrix = np.array(network1).reshape(4, 4)
"""
array([[0, 1, 0, 0],
       [0, 0, 1, 0],
       [0, 0, 1, 1],
       [0, 0, 1, 1]])
"""

coordinates = np.transpose(np.where(network1_matrix == 1))
"""
array([[0, 1],
       [1, 2],
       [2, 2],
       [2, 3],
       [3, 2],
       [3, 3]])
"""
result_df = pd.DataFrame({'1': coordinates[:, 0] + 1, '2': coordinates[:, 1] + 1})
result_df.columns = ['set', '']

result_df['set A :='] = result_df[['set', '']].apply(tuple, axis=1)
result_df = result_df.append({'set A :=': ';'}, ignore_index=True)

#result_df
result_df = result_df['set A :=']
result_df.to_csv('result.csv', sep=' ', float_format = True, index = False, quotechar= '\r')

!head result.csv

Output:

set A :=
(1, 2)
(2, 3)
(3, 3)
(3, 4)
(4, 3)
(4, 4)
;

Answer 2

Using Pandas is overkill here.

Here is a simplified version of the program, which correctly outputs CSV:

import csv

import numpy as np

arr = [0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 1, 1, 0, 0, 1, 1]
arr = np.array(arr).reshape(4, 4)
print(arr)

coords = np.where(arr == 1)
print(coords)

with open("resources/test.csv", "w") as file_out:
    writer = csv.writer(file_out)
    writer.writerow(('x', 'y'))
    writer.writerows(zip(*coords))

Contents of the output file:

x,y
0,1
1,2
2,2
2,3
3,2
3,3

If you want to output tuples, replace the context manager above with the following:

with open("resources/text.txt", "w") as file_out:
    for curr_coords in zip(*coords):
        file_out.write(str(curr_coords) + '\n')

Contents of the output file:

(0, 1)
(1, 2)
(2, 2)
(2, 3)
(3, 2)
(3, 3)