如何使用 openpyxl 在特定列上写入总计

Question

I have an excel spreadsheet with multiple columns. How can I iterate through particular columns and create a sum on the bottom. Number of rows is dynamic.

Answer 1

A simple but nice solution:

def sum_col(ws, col, col_top=2, tight=False):
    col_len = len(ws[col])
    if tight:
        col_len -= next(i for i, x in enumerate(reversed(ws[col])) if x.value is not None)
    ws[f'{col}{col_len + 1}'] = f'=SUM({col}{col_top}:{col}{col_len})'

If your example data sums.xlsx would look like:

"a",1,"b",2,"c"
"d",2,"e",2,"f"
"g",3,   , ,"h"
"i", ,   , ,

Then this:

from openpyxl import load_workbook


def sum_col(ws, col, col_top=2, tight=False):
    col_len = len(ws[col])
    if tight:
        col_len -= next(i for i, x in enumerate(reversed(ws[col])) if x.value is not None)
    ws[f'{col}{col_len + 1}'] = f'=SUM({col}{col_top}:{col}{col_len})'


wb = load_workbook('sums.xlsx')
ws = wb.active

sum_col(ws, 'B', col_top=1)
sum_col(ws, 'D', col_top=1, tight=True)
wb.save('changed_sums.xlsx')

Would result in:

"a",1,"b",2,"c"
"d",2,"e",2,"f"
"g",3,   ,4,"h"
"i", ,   , ,
   ,6,   , ,

(with 6 and 4 being the results of SUMs of course)

Note that col_top=1 is passed because the function assumes there's a one line header (which there isn't in the example). And the tight parameter causes the script to find the actual end of the column (first non-None cell) instead of what openpyxl thinks is the end of the column (which is basically just the number of rows with data).

Answer 2

This one does the trick. But if someone know better way, please provide.

from openpyxl import load_workbook
from xlsxwriter.utility import xl_rowcol_to_cell

# Get the number of rows 
df_len = len(df.index)

# list of column numbers that need to show sum at the bottom
col = [0, 2]

# iterating through those columns
for column in col:
    # Determine where we will place the formula
    cell_location = xl_rowcol_to_cell(df_len + 1, column)  # xl_rowcol_to_cell(RowNumber, ColumnNumber)
    # Get the range to use for the sum formula
    start_range = xl_rowcol_to_cell(1, column)  # row 1 (start from 0!) and  column 6 and so on
    end_range = xl_rowcol_to_cell(df_len, column)
    # Construct and write the formula
    formula = "=SUM({:s}:{:s})".format(start_range, end_range)  # {:s} substituted with "start_range" and "end_range" accordingly
    cell = ws[cell_location]
    cell.value = formula

wb.save('changed_sums.xlsx')