Create an add-in-enabled Excel instance with xlwings

It's too niche, but I'll show you the problems and solutions when creating an Excel instance with xlwings.

0. Environment

Check below.

• OS: Windows 10 (1809)
• Office 2016
• xlwings 0.20.7

1. Problems

To create an Excel instance with xlwings, use xw.apps.add () or xw.App (). However, this method has the following problems.

--For some reason, the add-in does not load. --After closing the instant, opening the workbook from Explorer does not load the add-in.

If you open only Excel without opening the workbook (start it from the start menu), the add-in will load normally.

2. Solution

Create an Excel instance from the shell and pass it to xlwings without using xw.apps.add () or xw.App ().

import re
import subprocess
import time
from pathlib import Path

import xlwings as xw

def get_xl_path() -> Path:
    #Function that returns the Excel installation path
    subprocess_rtn = (
        subprocess
        .run(['assoc','.xlsx'], shell=True, stdout = subprocess.PIPE, stderr = subprocess.PIPE)
        .stdout.decode("utf8")
    )
    assoc_to = re.search('Excel.Sheet.[0-9]+', subprocess_rtn).group()

    subprocess_rtn = (
        subprocess
        .run(['ftype', assoc_to], shell=True, stdout = subprocess.PIPE, stderr = subprocess.PIPE)
        .stdout.decode('utf-8')
    )
    xl_path = re.search('C:.*EXCEL.EXE', subprocess_rtn).group()

    return Path(xl_path)


def xw_apps_add_fixed() -> xw.App:
    #Function to create an Excel instance
    xl_path = get_xl_path()
    num = xw.apps.count
    pid = subprocess.Popen([str(xl_path),'/e']).pid

    #Wait until it can be recognized by xlwings
    while xw.apps.count == num:
        time.sleep(1)

    #Wait until available from xlwings
    while True:
        try:
            xw.apps[pid].activate()
            break
        except:
            time.sleep(1)

    return xw.apps[pid]


app = xw_apps_add_fixed()

reference

--Change file extension association at Windows command prompt