Openpyxl setting number format

This answer works with openpyxl 2.0. (The previously accepted answer does not.)

The number_format can be changed directly.

The given example becomes:

from openpyxl import Workbook

wb = Workbook()
ws = wb.create_sheet(title='testSheet')
_cell = ws.cell('A1')
_cell.number_format = '0.00E+00'

Note: this answer worked with earlier versions of openpyxl, but does not work with openpyxl 2.0

This is how to do it:

    _cell.style.number_format.format_code = '0.00E+00' 

To directly format cells using openpyxl version 3 (v3.0.9), the following code was required:

from openpyxl import Workbook

wb = Workbook()
ws = wb.create_sheet(title='testSheet')

_cell = ws['A1']
_cell.number_format = '0.00E+00'

The cell can be formatted directly as follows:

ws['A1'].number_format = '0.00E+00'

The documents show the various number formats available, and there are quite a few: https://openpyxl.readthedocs.io/en/stable/_modules/openpyxl/styles/numbers.html