Openpyxl & Python : column of keys, column of valu

Question

Apologies for the false start. I have now read the FAQs and hope my question meets the standards:). I have the following in a spreadsheet :

Col1        Col2
1234        12.5
1234        8.2
1234        9.8
2334        10.1
2334        7.7
4567        9.8
5678        9.9
5678        8.4

i need to total up the figures in Col2 for each reference number in Col1 using OpenPyxl & Python ie.

1234        30.5
2334        17.8
4567        9.8
5678        18.3

After a few false starts i have this :

#import modules
import openpyxl
from openpyxl.utils import coordinate_from_string, column_index_from_string
from openpyxl.utils.cell import _get_column_letter
import sys
from datetime import date
from datetime import time
import datetime
import calendar
from openpyxl.styles import Color, PatternFill, Font, Border
from shutil import copyfile

#set variables
dest_filename = 'P:\\Charging\\Chargeable Resources\\ChargeableActivity\\January2017ChargeableActivity.xlsx'
total = 0

#create objects
wb = openpyxl.load_workbook(filename = dest_filename, data_only=True)
ws1 = wb.get_sheet_by_name('ChargeableActivity')

for i in range(1, ws1.max_row):
    #convert ws1.cell(row=i, column=12).value to integer (=Excel convert to number)
    if isinstance(ws1.cell(row=i, column=12).value,long):
        RFCNumber = ws1.cell(row=i, column=12).value
        for col in ws1.iter_cols(min_col=12, max_col = 12, min_row=1):
            if ws1.cell(row=i, column=12).value == RFCNumber:
                total = total + ws1.cell(row=i, column=14).value
                print(RFCNumber,'Total=',total)

But the output is cumulative and doesn't delete duplicate RFC numbers :

Col1        Col2
    1234        12.5
    1234        20.7
    1234        30.5
    2334        40.6        
    4567        48.3        
    5678        58.1

etc I'm not a coder and am looking for a way to save a lot of time editing a big spreadsheet. Any suggestions welcomed. Thank you.

Answer 1

Try this code:

# Define a dict{} for key:value pairs
ref_total = {}

# Get Data from all rows
for row in ws.rows:
    # Slice cells A,B from row tuple
    cell_A = row[:1][0]
    cell_B = row[1:2][0]

    reference = cell_A.value
    if reference in ref_total.keys():
        ref_total[reference] += cell_B.value
    else:
        ref_total[reference] = cell_B.value

for key in sorted(ref_total.keys()):
    print('%s %s' % (key, ref_total[key]))

Tested with Python:3.4.2 - openpyxl:2.4.1 - LibreOffice: 4.3.3.2