带有字典的嵌套列表中的Python元素

Question

I have a project that requires me to read an Excel worksheet with openpyxl. In the worksheet I need to find several columns that have similar names, read the data in each column, and compare the values on each row, keeping only the rows that have identical values and storing a blank in the other rows.

I don't know how many columns are going to match the input string the user enters, and I don't know how many rows are going to be in the spreadsheet, so I've created a dictionary with the column headers as keys and the column values as lists.

How do I compare the values row-by row to find out if the values in each list match?

Here's the code that I have:

for row in range(1, num_rows):
        for cell in range(1, num_cols):
            header_row = str(work_sheet.cell(1, cell).value)
            cell_val = work_sheet.cell(row, cell).value
            cell_list.append(cell_val)
            if header_row in col_dict:
                col_dict[header_row].append(cell_val)
            else:
                col_dict[header_row] = [cell_val]

This gives me a dictionary like so:

{
    'Col B': ['Col B', 'x', 'x', None, 'x', 'x', 'x'], 
    'Col C': ['Col C', 'x', 'x', 'None', 'x', 'None', 'None'],
    'Col A': ['Col A', 'x', 'x', 'None', 'x', 'None', 'x']
}

I want to compare the elements at corresponding indices in each list(if ColB[1]=='x' and ColA[1]=='x' and ColC[1]=='x' , put an 'x' in output_list . Else, put a "" in that index of the output list. I can see the lists, but how do I compare the elements in them?

for key in col_dict.keys():
        for i in range(len(col_dict[key])):
            print(col_dict[key][i])

Answer 1

I eventually figured out the answer: I created a new list, then iterated through each column. If a value in the column matched 'x', I wrote 'x' to the new list. If the value did not match 'x', or if the value in the the new list was 'None,' I placed 'None' in the new dict. The else clause handles the first copies the first list in the dictionary into the new list so the other dictionary entries are compared to the new list. Here's the solution:

                            if cell_val is None:
                                cell_val = ''
                            new_list.append(cell_val)
                            if column_name in new_list:
                                new_list[column_name].append(cell_val)
                            else:
                                new_list[column_name] = [cell_val]