How to populating a matrix using a list of lists in python?-CodePudding

So I am unsure as to why I am running into an issue for this very simple task. I have a list of lists called temp that is initialized like this:

temp = [['1', '2', '3', '4', '5', '6', '7', '8', '9', '10', '11', '12', '13', '14', '15', '16', '17', '18', '19', '20', '21', '22', '23', '24', '25', '26', '27', '28', '29', '30', '31', '32', '33', '34', '35', '36', '37', '38', '39', '40', '41', '42', '43', '44', '45', '46', '47', '48', '49', '50', '51', '52', '53', '54', '55', '56', '57', '58', '59', '60', '61', '62', '63', '64', '65', '66', '67', '68', '69', '70', '71', '72', '73', '74', '75', '76', '77', '78', '79', '80', '81', '82', '83', '84', '85', '86', '87', '88', '89', '90', '91', '92', '93', '94', '95', '96', '97', '98', '99', '100', '101', '102', '103', '104', '105', '106', '107', '108', '109', '110', '111', '112', '113', '114', '115', '116', '117', '118', '119', '120', '121', '122', '123', '124', '125', '126', '127', '128', '129', '130', '131', '132', '133', '134', '135', '136', '137', '138', '139', '140', '141', '142', '143', '144', '145', '146', '147', '148', '149', '150', '151', '152', '153', '154', '155', '156', '157', '158', '159', '160', '161', '162', '163', '164', '165', '166', '167', '168', '169', '170', '171', '172', '173', '174', '175', '176', '177', '178', '179', '180', '181', '182', '183', '184', '185', '186', '187', '188', '189', '190', '191', '192', '193', '194', '195', '196', '197', '198', '199', '200', '201', '202', '203', '204', '205', '206', '207', '208', '209', '210', '211', '212', '213', '214', '215', '216', '217', '218', '219', '220', '221', '222', '223', '224', '225', '226', '227', '228', '229', '230', '231', '232', '233', '234', '235', '236', '237', '238', '239', '240\n'], ['11', '14', '16', '2', '10', '1', '4', '8', '26', '6', '5', '33', '41', '12', '53', '3', '7', '77', '9', '13', '21', '65', '60', '42', '35', '15', '17', '44', '22', '36', '75', '28', '20', '25', '56', '96', '24', '39', '18', '31', '38', '19', '34', '43', '32', '29', '46', '55', '37', '45', '30', '94', '51', '66', '89', '27', '49', '64', '48', '52', '50', '40', '23', '47', '72', '63', '69', '71', '208', '68', '74', '95', '59', '62', '86', '78', '70', '102', '129', '58', '67', '79', '101', '84', '73', '92', '76', '80', '57', '91', '82', '61', '88', '90', '93', '97', '103', '87', '134', '98', '99', '83', '113', '81', '111', '121', '135', '107', '117', '109', '105', '108', '104', '112', '100', '118', '110', '115', '128', '116', '85', '122', '133', '131', '119', '126', '124', '114', '179', '132', '210', '142', '152', '127', '155', '149', '120', '180', '141', '144', '139', '138', '130', '147', '240', '145', '185', '136', '173', '148', '143', '146', '162', '163', '137', '156', '188', '153', '157', '165', '154', '158', '160', '164', '175', '167', '159', '170', '150', '172', '166', '161', '182', '178', '183', '177', '184', '181', '151', '176', '187', '186', '169', '174', '190', '123', '194', '189', '196', '168', '204', '197', '200', '201', '195', '199', '198', '193', '192', '191', '202', '106', '206', '203', '125', '207', '218', '140', '205', '214', '221', '212', '217', '220', '209', '215', '216', '219', '224', '230', '213', '222', '223', '229', '227', '211', '225', '228', '226', '234', '232', '233', '231', '171', '235', '236', '238', '237', '239', '54\n'], ['114', '8', '94', '26', '33', '17', '14', '7', '64', '173', '4', '10', '11', '60', '41', '9', '53', '19', '42', '30', '52', '43', '49', '40', '21', '89', '37', '27', '29', '13', '34', '24', '95', '25', '39', '70', '63', '79', '75', '56', '77', '28', '69', '50', '73', '32', '101', '82', '72', '57', '96', '83', '88', '58', '61', '129', '109', '71', '120', '78', '76', '80', '87', '68', '98', '99', '110', '102', '115', '127', '118', '117', '104', '122', '138', '97', '133', '153', '137', '160', '126', '204', '128', '184', '234', '176', '131', '213', '85', '145', '177', '163', '152', '148', '189', '201', '183', '164', '168', '158', '150', '171', '162', '143', '172', '151', '161', '159', '211', '175', '141', '165', '200', '125', '219', '149', '155', '222', '202', '216', '209', '192', '182', '223', '212', '190', '224', '106', '215', '221', '205', '218', '236', '229', '225', '180', '198', '233', '231', '228', '232', '227', '235', '238', '237', '140', '239', '210', '217', '16', '23', '157', '170', '194', '185', '12', '119', '156', '92', '179', '6', '107', '44', '35', '20', '174', '103', '154', '147', '51', '67', '135', '191', '47', '2', '48', '214', '136', '197', '226', '100', '112', '134', '116', '208', '55', '187', '144', '3', '142', '1', '84', '15', '203', '123', '65', '186', '130', '46', '59', '36', '62', '18', '22', '81', '193', '169', '45', '206', '31', '105', '91', '132', '90', '178', '230', '146', '199', '66', '86', '121', '54', '74', '5', '108', '195', '188', '207', '167', '113', '93', '38', '111', '139', '220', '181', '196', '124', '166', '240\n'], ['1', '2', '33', '6', '4', '5', '7', '14', '12', '16', '8', '64', '11', '9', '17', '18', '20', '28', '13', '24', '19', '31', '21', '41', '40', '30', '22', '94', '35', '47', '27', '60', '25', '45', '34', '37', '29', '43', '69', '15', '3', '89', '65', '56', '53', '49', '38', '48', '42', '26', '59', '39', '72', '52', '129', '63', '10', '66', '67', '50', '23', '62', '79', '93', '36', '55', '82', '73', '78', '46', '32', '84', '57', '71', '54', '81', '98', '70', '58', '102', '88', '77', '90', '86', '104', '108', '95', '68', '96', '51', '101', '100', '75', '103', '80', '122', '99', '112', '92', '83', '135', '109', '105', '110', '115', '76', '61', '74', '117', '118', '179', '44', '128', '121', '120', '87', '126', '127', '114', '107', '133', '124', '134', '116', '111', '139', '113', '132', '130', '143', '138', '154', '91', '145', '240', '160', '148', '136', '119', '137', '153', '142', '173', '152', '97', '144', '159', '164', '162', '85', '131', '146', '157', '167', '174', '210', '156', '178', '188', '176', '158', '166', '170', '175', '169', '151', '204', '165', '147', '177', '172', '187', '183', '186', '181', '163', '189', '196', '149', '184', '191', '123', '180', '190', '168', '199', '155', '171', '106', '195', '201', '200', '192', '197', '150', '193', '209', '211', '203', '182', '205', '194', '202', '161', '206', '213', '207', '212', '214', '219', '208', '218', '217', '125', '216', '220', '215', '224', '221', '222', '230', '140', '185', '223', '231', '198', '225', '227', '234', '229', '228', '226', '233', '236', '235', '232', '141', '237', '238', '239\n']]

I also have an empty matrix that has rows that are equal to the length of temp[0] and columns that are equal to the length of temp which in this case would be a 240x4 sized matrix.

Here is my current code to read over each list in temp, find the row that I want to populate which is equal to the value of the list[i]-1 and set this row to the index which is i. I am only doing this for the first column as of now.

for test in temp:
   for i in range(len(test)):
      #print("Entry: ("   str(test[i])   ",0) populated with index: "   str(i 1))
      row = int(test[i])-1
      val = i 1
      matrix[row][0] = val

I would expect the first column of matrix to just be 1, 2,...,240. However after printing out matrix I get the following:

matrix = [[1, 0, 0, 0], [2, 0, 0, 0], [41, 0, 0, 0], [5, 0, 0, 0], [6, 0, 0, 0], [4, 0, 0, 0], [7, 0, 0, 0], [11, 0, 0, 0], [14, 0, 0, 0], [57, 0, 0, 0], [13, 0, 0, 0], [9, 0, 0, 0], [19, 0, 0, 0], [8, 0, 0, 0], [40, 0, 0, 0], [10, 0, 0, 0], [15, 0, 0, 0], [16, 0, 0, 0], [21, 0, 0, 0], [17, 0, 0, 0], [23, 0, 0, 0], [27, 0, 0, 0], [61, 0, 0, 0], [20, 0, 0, 0], [33, 0, 0, 0], [50, 0, 0, 0], [31, 0, 0, 0], [18, 0, 0, 0], [37, 0, 0, 0], [26, 0, 0, 0], [22, 0, 0, 0], [71, 0, 0, 0], [3, 0, 0, 0], [35, 0, 0, 0], [29, 0, 0, 0], [65, 0, 0, 0], [36, 0, 0, 0], [47, 0, 0, 0], [52, 0, 0, 0], [25, 0, 0, 0], [24, 0, 0, 0], [49, 0, 0, 0], [38, 0, 0, 0], [112, 0, 0, 0], [34, 0, 0, 0], [70, 0, 0, 0], [30, 0, 0, 0], [48, 0, 0, 0], [46, 0, 0, 0], [60, 0, 0, 0], [90, 0, 0, 0], [54, 0, 0, 0], [45, 0, 0, 0], [75, 0, 0, 0], [66, 0, 0, 0], [44, 0, 0, 0], [73, 0, 0, 0], [79, 0, 0, 0], [51, 0, 0, 0], [32, 0, 0, 0], [107, 0, 0, 0], [62, 0, 0, 0], [56, 0, 0, 0], [12, 0, 0, 0], [43, 0, 0, 0], [58, 0, 0, 0], [59, 0, 0, 0], [88, 0, 0, 0], [39, 0, 0, 0], [78, 0, 0, 0], [74, 0, 0, 0], [53, 0, 0, 0], [68, 0, 0, 0], [108, 0, 0, 0], [93, 0, 0, 0], [106, 0, 0, 0], [82, 0, 0, 0], [69, 0, 0, 0], [63, 0, 0, 0], [95, 0, 0, 0], [76, 0, 0, 0], [67, 0, 0, 0], [100, 0, 0, 0], [72, 0, 0, 0], [150, 0, 0, 0], [84, 0, 0, 0], [116, 0, 0, 0], [81, 0, 0, 0], [42, 0, 0, 0], [83, 0, 0, 0], [133, 0, 0, 0], [99, 0, 0, 0], [64, 0, 0, 0], [28, 0, 0, 0], [87, 0, 0, 0], [89, 0, 0, 0], [145, 0, 0, 0], [77, 0, 0, 0], [97, 0, 0, 0], [92, 0, 0, 0], [91, 0, 0, 0], [80, 0, 0, 0], [94, 0, 0, 0], [85, 0, 0, 0], [103, 0, 0, 0], [189, 0, 0, 0], [120, 0, 0, 0], [86, 0, 0, 0], [102, 0, 0, 0], [104, 0, 0, 0], [125, 0, 0, 0], [98, 0, 0, 0], [127, 0, 0, 0], [119, 0, 0, 0], [105, 0, 0, 0], [124, 0, 0, 0], [109, 0, 0, 0], [110, 0, 0, 0], [139, 0, 0, 0], [115, 0, 0, 0], [114, 0, 0, 0], [96, 0, 0, 0], [182, 0, 0, 0], [122, 0, 0, 0], [214, 0, 0, 0], [117, 0, 0, 0], [118, 0, 0, 0], [113, 0, 0, 0], [55, 0, 0, 0], [129, 0, 0, 0], [151, 0, 0, 0], [128, 0, 0, 0], [121, 0, 0, 0], [123, 0, 0, 0], [101, 0, 0, 0], [138, 0, 0, 0], [140, 0, 0, 0], [131, 0, 0, 0], [126, 0, 0, 0], [222, 0, 0, 0], [237, 0, 0, 0], [142, 0, 0, 0], [130, 0, 0, 0], [146, 0, 0, 0], [134, 0, 0, 0], [152, 0, 0, 0], [169, 0, 0, 0], [137, 0, 0, 0], [179, 0, 0, 0], [195, 0, 0, 0], [166, 0, 0, 0], [144, 0, 0, 0], [141, 0, 0, 0], [132, 0, 0, 0], [187, 0, 0, 0], [157, 0, 0, 0], [153, 0, 0, 0], [161, 0, 0, 0], [147, 0, 0, 0], [136, 0, 0, 0], [204, 0, 0, 0], [149, 0, 0, 0], [176, 0, 0, 0], [148, 0, 0, 0], [168, 0, 0, 0], [162, 0, 0, 0], [154, 0, 0, 0], [185, 0, 0, 0], [165, 0, 0, 0], [163, 0, 0, 0], [188, 0, 0, 0], [171, 0, 0, 0], [143, 0, 0, 0], [155, 0, 0, 0], [164, 0, 0, 0], [160, 0, 0, 0], [170, 0, 0, 0], [158, 0, 0, 0], [111, 0, 0, 0], [183, 0, 0, 0], [175, 0, 0, 0], [200, 0, 0, 0], [173, 0, 0, 0], [180, 0, 0, 0], [223, 0, 0, 0], [174, 0, 0, 0], [172, 0, 0, 0], [159, 0, 0, 0], [177, 0, 0, 0], [184, 0, 0, 0], [181, 0, 0, 0], [193, 0, 0, 0], [196, 0, 0, 0], [202, 0, 0, 0], [190, 0, 0, 0], [178, 0, 0, 0], [194, 0, 0, 0], [226, 0, 0, 0], [186, 0, 0, 0], [192, 0, 0, 0], [191, 0, 0, 0], [203, 0, 0, 0], [199, 0, 0, 0], [167, 0, 0, 0], [201, 0, 0, 0], [205, 0, 0, 0], [207, 0, 0, 0], [211, 0, 0, 0], [197, 0, 0, 0], [156, 0, 0, 0], [198, 0, 0, 0], [208, 0, 0, 0], [206, 0, 0, 0], [209, 0, 0, 0], [217, 0, 0, 0], [215, 0, 0, 0], [213, 0, 0, 0], [212, 0, 0, 0], [210, 0, 0, 0], [216, 0, 0, 0], [219, 0, 0, 0], [220, 0, 0, 0], [224, 0, 0, 0], [218, 0, 0, 0], [227, 0, 0, 0], [232, 0, 0, 0], [228, 0, 0, 0], [231, 0, 0, 0], [230, 0, 0, 0], [221, 0, 0, 0], [225, 0, 0, 0], [236, 0, 0, 0], [233, 0, 0, 0], [229, 0, 0, 0], [235, 0, 0, 0], [234, 0, 0, 0], [238, 0, 0, 0], [239, 0, 0, 0], [240, 0, 0, 0], [135, 0, 0, 0]]

For some reason column 0 is not following the 1,2,...,240 that I would expect. If the for loop is just going from 0...240 I thought it would be fairly simple to just set the row to that index. I would expect row 3 for example to have a 3 now in the first column, not a 41. Are there any suggestions to fix this?

Here is a smaller test case:

matrix = [[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]]
temp = [[1,2,3,4,5], [5,4,3,2,1],[1,4,5,3,2]]
for test in temp:
    for i in range(len(test)):
        #print("Entry: ("   str(test[i])   ",0) populated with index: "   str(i 1))
        row = int(test[i])-1
        val = i 1
        matrix[row][0] = val
print(matrix)

This outputs:

matrix = [[1, 0, 0, 0, 0], [5, 0, 0, 0, 0], [4, 0, 0, 0, 0], [2, 0, 0, 0, 0], [3, 0, 0, 0, 0]]

I would expect the first col. to be 1,2,3,4,5 but it is instead 1,5,4,2,3.

CodePudding user response：

You can avoid all those nested loops with inconvenient index adjustments and conversions using numpy array with short and flexible array indexing:

import numpy as np

matrix = np.array([[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]])
temp = np.array([[1,2,3,4,5], [5,4,3,2,1], [1,4,5,3,2]])

matrix[:, 0] = temp[0]
print(matrix)

[[1 0 0 0 0]
 [2 0 0 0 0]
 [3 0 0 0 0]
 [4 0 0 0 0]
 [5 0 0 0 0]]

CodePudding user response：

If I understand correctly, what you want to do is basically transpose the original matrix. If that is the case, you can just use numpy transpose function:

import numpy as np

temp = [[1,2,3,4,5], [5,4,3,2,1],[1,4,5,3,2]]

temp_np = np.array(temp)
result_np = temp_np.T
result = result_np.tolist()
print(result)

Result:

[[1, 5, 1], [2, 4, 4], [3, 3, 5], [4, 2, 3], [5, 1, 2]]