• Re: How to replace a cell value with each of its contour cells and yiel

    From Thomas Passin@21:1/5 to marc nicole via Python-list on Sun Jan 21 09:14:45 2024
    On 1/21/2024 7:37 AM, marc nicole via Python-list wrote:
    Hello,

    I have an initial dataframe with a random list of target cells (each cell being identified with a couple (x,y)).
    I want to yield four different dataframes each containing the value of one
    of the contour (surrounding) cells of each specified target cell.

    the surrounding cells to consider for a specific target cell are : (x-1,y), (x,y-1),(x+1,y);(x,y+1), specifically I randomly choose 1 to 4 cells from these and consider for replacement to the target cell.

    I want to do that through a pandas-specific approach without having to
    define the contour cells separately and then apply the changes on the dataframe

    1. Why do you want a Pandas-specific approach? Many people would rather
    keep code independent of special libraries if possible;

    2. How big can these collections of target cells be, roughly speaking?
    The size could make a big difference in picking a design;

    3. You really should work on formatting code for this list. Your code
    below is very complex and would take a lot of work to reformat to the
    point where it is readable, especially with the nearly impenetrable
    arguments in some places. Probably all that is needed is to replace all
    tabs by (say) three spaces, and to make sure you intentionally break
    lines well before they might get word-wrapped. Here is one example I
    have reformatted (I hope I got this right):

    list_tuples_idx_cells_all_datasets = list(filter(
    lambda x: utils_tuple_list_not_contain_nan(x),
    [list(tuples) for tuples in list(
    itertools.product(*target_cells_with_contour))
    ]))

    4. As an aside, it doesn't look like you need to convert all those
    sequences and iterators to lists all over the place;


    (but rather using an all in one approach):
    for now I have written this example which I think is not Pandas specific:
    [snip]

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  • From Thomas Passin@21:1/5 to marc nicole on Sun Jan 21 12:18:31 2024
    On 1/21/2024 11:54 AM, marc nicole wrote:
    Thanks for the reply,

    I think using a Pandas (or a Numpy) approach would optimize the
    execution of the program.

    Target cells could be up to 10% the size of the dataset, a good example
    to start with would have from 10 to 100 values.

    Thanks for the reformatted code. It's much easier to read and think about.

    For say 100 points, it doesn't seem that "optimization" would be much of
    an issue. On my laptop machine and Python 3.12, your example takes
    around 5 seconds to run and print(). OTOH if you think you will go to
    much larger datasets, certainly execution time could become a factor.

    I would think that NumPy arrays and/or matrices would have good potential.

    Is this some kind of a cellular automaton, or an image filtering process?

    Let me know your thoughts, here's a reproducible example which I formatted:



    from numpy import random
    import pandas as pd
    import numpy as np
    import operator
    import math
    from collections import deque
    from queue import *
    from queue import Queue
    from itertools import product


    def select_target_values(dataframe, number_of_target_values):
        target_cells = []
        for _ in range(number_of_target_values):
            row_x = random.randint(0, len(dataframe.columns) - 1)
            col_y = random.randint(0, len(dataframe) - 1)
            target_cells.append((row_x, col_y))
        return target_cells


    def select_contours(target_cells):
        contour_coordinates = [(0, 1), (1, 0), (0, -1), (-1, 0)]
        contour_cells = []
        for target_cell in target_cells:
            # random contour count for each cell
            contour_cells_count = random.randint(1, 4)
            try:
                contour_cells.append(
                    [
                        tuple(
                            map(
                                lambda i, j: i + j,
                                (target_cell[0], target_cell[1]),
                                contour_coordinates[iteration_],
                            )
                        )
                        for iteration_ in range(contour_cells_count)
                    ]
                )
            except IndexError:
                continue
        return contour_cells


    def create_zipf_distribution():
        zipf_dist = random.zipf(2, size=(50, 5)).reshape((50, 5))

        zipf_distribution_dataset = pd.DataFrame(zipf_dist).round(3)

        return zipf_distribution_dataset


    def apply_contours(target_cells, contour_cells):
        target_cells_with_contour = []
        # create one single list of cells
        for idx, target_cell in enumerate(target_cells):
            target_cell_with_contour = [target_cell]
            target_cell_with_contour.extend(contour_cells[idx])
            target_cells_with_contour.append(target_cell_with_contour)
        return target_cells_with_contour


    def create_possible_datasets(dataframe, target_cells_with_contour):
        all_datasets_final = []
        dataframe_original = dataframe.copy()

        list_tuples_idx_cells_all_datasets = list(
            filter(
                lambda x: x,
                [list(tuples) for tuples in list(product(*target_cells_with_contour))],
            )
        )
        target_original_cells_coordinates = list(
            map(
                lambda x: x[0],
                [
                    target_and_contour_cell
                    for target_and_contour_cell in target_cells_with_contour
                ],
            )
        )
        for dataset_index_values in list_tuples_idx_cells_all_datasets:
            all_datasets = []
            for idx_cell in range(len(dataset_index_values)):
                dataframe_cpy = dataframe.copy()
                dataframe_cpy.iat[
                    target_original_cells_coordinates[idx_cell][1],
                    target_original_cells_coordinates[idx_cell][0],
                ] = dataframe_original.iloc[
                    dataset_index_values[idx_cell][1], dataset_index_values[idx_cell][0]
                ]
                all_datasets.append(dataframe_cpy)
            all_datasets_final.append(all_datasets)
        return all_datasets_final


    def main():
        zipf_dataset = create_zipf_distribution()

        target_cells = select_target_values(zipf_dataset, 5)
        print(target_cells)
        contour_cells = select_contours(target_cells)
        print(contour_cells)
        target_cells_with_contour = apply_contours(target_cells, contour_cells)
        datasets = create_possible_datasets(zipf_dataset, target_cells_with_contour)
        print(datasets)


    main()

    Le dim. 21 janv. 2024 à 16:33, Thomas Passin via Python-list <python-list@python.org <mailto:python-list@python.org>> a écrit :

    On 1/21/2024 7:37 AM, marc nicole via Python-list wrote:
    > Hello,
    >
    > I have an initial dataframe with a random list of target cells
    (each cell
    > being identified with a couple (x,y)).
    > I want to yield four different dataframes each containing the
    value of one
    > of the contour (surrounding) cells of each specified target cell.
    >
    > the surrounding cells to consider for a specific target cell are
    : (x-1,y),
    > (x,y-1),(x+1,y);(x,y+1), specifically I randomly choose 1 to 4
    cells from
    > these and consider for replacement to the target cell.
    >
    > I want to do that through a pandas-specific approach without
    having to
    > define the contour cells separately and then apply the changes on the
    > dataframe

    1. Why do you want a Pandas-specific approach?  Many people would
    rather
    keep code independent of special libraries if possible;

    2. How big can these collections of target cells be, roughly speaking?
    The size could make a big difference in picking a design;

    3. You really should work on formatting code for this list.  Your code
    below is very complex and would take a lot of work to reformat to the
    point where it is readable, especially with the nearly impenetrable
    arguments in some places.  Probably all that is needed is to replace
    all
    tabs by (say) three spaces, and to make sure you intentionally break
    lines well before they might get word-wrapped.  Here is one example I
    have reformatted (I hope I got this right):

    list_tuples_idx_cells_all_datasets = list(filter(
        lambda x: utils_tuple_list_not_contain_nan(x),
        [list(tuples) for tuples in list(
              itertools.product(*target_cells_with_contour))
        ]))

    4. As an aside, it doesn't look like you need to convert all those
    sequences and iterators to lists all over the place;


    > (but rather using an all in one approach):
    > for now I have written this example which I think is not Pandas
    specific:
    [snip]

    --
    https://mail.python.org/mailman/listinfo/python-list
    <https://mail.python.org/mailman/listinfo/python-list>


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  • From Thomas Passin@21:1/5 to marc nicole on Sun Jan 21 22:57:02 2024
    On 1/21/2024 1:25 PM, marc nicole wrote:
    It is part of a larger project aiming at processing data according to a
    given algorithm
    Do you have any comments or any enhancing recommendations on the code?

    I'm not knowledgeable enough about either pandas or numpy, I'm afraid,
    just very basic usage. Someone else will probably pitch in.

    Thanks.

    Le dim. 21 janv. 2024 à 18:28, Thomas Passin via Python-list <python-list@python.org <mailto:python-list@python.org>> a écrit :

    On 1/21/2024 11:54 AM, marc nicole wrote:
    > Thanks for the reply,
    >
    > I think using a Pandas (or a Numpy) approach would optimize the
    > execution of the program.
    >
    > Target cells could be up to 10% the size of the dataset, a good
    example
    > to start with would have from 10 to 100 values.

    Thanks for the reformatted code.  It's much easier to read and think
    about.

    For say 100 points, it doesn't seem that "optimization" would be
    much of
    an issue.  On my laptop machine and Python 3.12, your example takes
    around 5 seconds to run and print().  OTOH if you think you will go to
    much larger datasets, certainly execution time could become a factor.

    I would think that NumPy arrays and/or matrices would have good
    potential.

    Is this some kind of a cellular automaton, or an image filtering
    process?

    > Let me know your thoughts, here's a reproducible example which I
    formatted:
    >
    >
    >
    > from numpy import random
    > import pandas as pd
    > import numpy as np
    > import operator
    > import math
    > from collections import deque
    > from queue import *
    > from queue import Queue
    > from itertools import product
    >
    >
    > def select_target_values(dataframe, number_of_target_values):
    >      target_cells = []
    >      for _ in range(number_of_target_values):
    >          row_x = random.randint(0, len(dataframe.columns) - 1)
    >          col_y = random.randint(0, len(dataframe) - 1)
    >          target_cells.append((row_x, col_y))
    >      return target_cells
    >
    >
    > def select_contours(target_cells):
    >      contour_coordinates = [(0, 1), (1, 0), (0, -1), (-1, 0)]
    >      contour_cells = []
    >      for target_cell in target_cells:
    >          # random contour count for each cell
    >          contour_cells_count = random.randint(1, 4)
    >          try:
    >              contour_cells.append(
    >                  [
    >                      tuple(
    >                          map(
    >                              lambda i, j: i + j,
    >                              (target_cell[0], target_cell[1]),
    >                              contour_coordinates[iteration_],
    >                          )
    >                      )
    >                      for iteration_ in range(contour_cells_count)
    >                  ]
    >              )
    >          except IndexError:
    >              continue
    >      return contour_cells
    >
    >
    > def create_zipf_distribution():
    >      zipf_dist = random.zipf(2, size=(50, 5)).reshape((50, 5))
    >
    >      zipf_distribution_dataset = pd.DataFrame(zipf_dist).round(3)
    >
    >      return zipf_distribution_dataset
    >
    >
    > def apply_contours(target_cells, contour_cells):
    >      target_cells_with_contour = []
    >      # create one single list of cells
    >      for idx, target_cell in enumerate(target_cells):
    >          target_cell_with_contour = [target_cell]
    >          target_cell_with_contour.extend(contour_cells[idx])
    >          target_cells_with_contour.append(target_cell_with_contour)
    >      return target_cells_with_contour
    >
    >
    > def create_possible_datasets(dataframe, target_cells_with_contour):
    >      all_datasets_final = []
    >      dataframe_original = dataframe.copy()
    >
    >      list_tuples_idx_cells_all_datasets = list(
    >          filter(
    >              lambda x: x,
    >              [list(tuples) for tuples in
    > list(product(*target_cells_with_contour))],
    >          )
    >      )
    >      target_original_cells_coordinates = list(
    >          map(
    >              lambda x: x[0],
    >              [
    >                  target_and_contour_cell
    >                  for target_and_contour_cell in
    target_cells_with_contour
    >              ],
    >          )
    >      )
    >      for dataset_index_values in list_tuples_idx_cells_all_datasets:
    >          all_datasets = []
    >          for idx_cell in range(len(dataset_index_values)):
    >              dataframe_cpy = dataframe.copy()
    >              dataframe_cpy.iat[
    >                  target_original_cells_coordinates[idx_cell][1],
    >                  target_original_cells_coordinates[idx_cell][0],
    >              ] = dataframe_original.iloc[
    >                  dataset_index_values[idx_cell][1],
    > dataset_index_values[idx_cell][0]
    >              ]
    >              all_datasets.append(dataframe_cpy)
    >          all_datasets_final.append(all_datasets)
    >      return all_datasets_final
    >
    >
    > def main():
    >      zipf_dataset = create_zipf_distribution()
    >
    >      target_cells = select_target_values(zipf_dataset, 5)
    >      print(target_cells)
    >      contour_cells = select_contours(target_cells)
    >      print(contour_cells)
    >      target_cells_with_contour = apply_contours(target_cells,
    contour_cells)
    >      datasets = create_possible_datasets(zipf_dataset,
    > target_cells_with_contour)
    >      print(datasets)
    >
    >
    > main()
    >
    > Le dim. 21 janv. 2024 à 16:33, Thomas Passin via Python-list
    > <python-list@python.org <mailto:python-list@python.org>
    <mailto:python-list@python.org <mailto:python-list@python.org>>> a
    écrit :
    >
    >     On 1/21/2024 7:37 AM, marc nicole via Python-list wrote:
    >      > Hello,
    >      >
    >      > I have an initial dataframe with a random list of target cells
    >     (each cell
    >      > being identified with a couple (x,y)).
    >      > I want to yield four different dataframes each containing the
    >     value of one
    >      > of the contour (surrounding) cells of each specified
    target cell.
    >      >
    >      > the surrounding cells to consider for a specific target
    cell are
    >     : (x-1,y),
    >      > (x,y-1),(x+1,y);(x,y+1), specifically I randomly choose 1 to 4
    >     cells from
    >      > these and consider for replacement to the target cell.
    >      >
    >      > I want to do that through a pandas-specific approach without
    >     having to
    >      > define the contour cells separately and then apply the
    changes on the
    >      > dataframe
    >
    >     1. Why do you want a Pandas-specific approach?  Many people would
    >     rather
    >     keep code independent of special libraries if possible;
    >
    >     2. How big can these collections of target cells be, roughly
    speaking?
    >     The size could make a big difference in picking a design;
    >
    >     3. You really should work on formatting code for this list.
    Your code
    >     below is very complex and would take a lot of work to
    reformat to the
    >     point where it is readable, especially with the nearly
    impenetrable
    >     arguments in some places.  Probably all that is needed is to
    replace
    >     all
    >     tabs by (say) three spaces, and to make sure you
    intentionally break
    >     lines well before they might get word-wrapped.  Here is one
    example I
    >     have reformatted (I hope I got this right):
    >
    >     list_tuples_idx_cells_all_datasets = list(filter(
    >          lambda x: utils_tuple_list_not_contain_nan(x),
    >          [list(tuples) for tuples in list(
    >                itertools.product(*target_cells_with_contour))
    >          ]))
    >
    >     4. As an aside, it doesn't look like you need to convert all
    those
    >     sequences and iterators to lists all over the place;
    >
    >
    >      > (but rather using an all in one approach):
    >      > for now I have written this example which I think is not
    Pandas
    >     specific:
    >     [snip]
    >
    >     --
    > https://mail.python.org/mailman/listinfo/python-list
    <https://mail.python.org/mailman/listinfo/python-list>
    >     <https://mail.python.org/mailman/listinfo/python-list
    <https://mail.python.org/mailman/listinfo/python-list>>
    >

    --
    https://mail.python.org/mailman/listinfo/python-list
    <https://mail.python.org/mailman/listinfo/python-list>


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