Pyinstaller: Module not found when running .exe - pyinstaller

Question

I have a problem which I have reduced to a small program. The program tries to write a Pandas dataframe. This works find in PyCharm, but when I produce an exe using PyInstaller it errors at runtime:
.\pyinst_excel.exe
Traceback (most recent call last):
File "pyinst_excel.py", line 31, in <module>
File "pyinst_excel.py", line 25, in add_generated_files_row
File "site-packages\pandas\io\excel\_openpyxl.py", line 18, in __init__
ModuleNotFoundError: No module named 'openpyxl'
[11408] Failed to execute script pyinst_excel
Now I have tried explicitly importing openpyxl and that didn't work and I have also used --hidden-import:
call venv\Scripts\activate
pyinstaller --onefile --hidden-import _openpyxl --hidden-import openpyxl --clean pyinst_excel.py
The generated spec file looks like this:
# -*- mode: python ; coding: utf-8 -*-
block_cipher = None
a = Analysis(['pyinst_excel.py'],
pathex=['D:\\Development\\OEM-SR-Rules'],
binaries=[],
datas=[],
hiddenimports=['_openpyxl', 'openpyxl'],
hookspath=[],
runtime_hooks=[],
excludes=[],
win_no_prefer_redirects=False,
win_private_assemblies=False,
cipher=block_cipher,
noarchive=False)
pyz = PYZ(a.pure, a.zipped_data,
cipher=block_cipher)
exe = EXE(pyz,
a.scripts,
a.binaries,
a.zipfiles,
a.datas,
[],
name='pyinst_excel',
debug=False,
bootloader_ignore_signals=False,
strip=False,
upx=True,
upx_exclude=[],
runtime_tmpdir=None,
console=True )
However this doesn't fix the problem. From the build/warnings file I see:
...
missing module named openpyxl - imported by pandas.io.excel._openpyxl (delayed, conditional), D:\Development\OEM-SR-Rules\pyinst_excel.py (top-level)
...
missing module named 'openpyxl.styles' - imported by pandas.io.excel._openpyxl (delayed)
missing module named 'openpyxl.style' - imported by pandas.io.excel._openpyxl (delayed)
Program code:
import argparse
from operator import attrgetter
import os
import sys
import json
import pandas as pd
import numpy as np
from pathlib import Path
import glob
import re
import time
from sys import exit
from shutil import copyfile
REPORT_DATE_FMT = '%d-%m-%Y %H.%M'
def add_generated_files_row(generated_excel, sequence: int, date_generated):
# gen_files_df = pd.read_excel(generated_files_excel, index_col=0)
gen_files_df = pd.DataFrame(columns=['Sequence', 'Date Generated'])
new_row = {'Sequence': sequence,
'Date Generated': date_generated}
gen_files_df = gen_files_df.append(new_row, ignore_index=True, sort=False)
writer = pd.ExcelWriter(generated_excel)
gen_files_df.to_excel(writer)
generated_files_excel = Path('D:\temp\test.xlsx')
date_generated = time.strftime(f"{REPORT_DATE_FMT}")
add_generated_files_row(generated_files_excel, 1, date_generated)
I am using Python 3.8 and PyInstaller 3.6.
I am out of ideas. Any help would be much appreciated.
Thanks,
Clive

Answer 1

The problem turned out to be caused PyInstaller being run from a different environment.
To solve this I had to do:
venv\Scripts\activate.bat
(venv) D:\Development\OEM-SR-Rules>pip install PyInstaller