openpyxl decimal/float formatting problem

repro.py

from openpyxl.workbook import Workbook
from openpyxl.writer.excel import save_virtual_workbook, save_workbook
from openpyxl.reader.excel import load_workbook
from decimal import Decimal
import tempfile
import os


def get_filepath(name):
    fh, path = tempfile.mkstemp(prefix=name, suffix='.xlsx')
    os.close(fh)
    return path

def unoptimized(decnum):
    wb = Workbook()
    ws = wb.get_active_sheet()
    cell = ws.cell(row=1, column=1)
    cell.value = float(decnum)
    # FIX: the below works in 2.1.0
    # cell.set_explicit_value(value='%.2f' % value, data_type=cell.TYPE_NUMERIC)
    filepath = get_filepath('optimized')
    save_workbook(wb, filepath)
    return filepath


def optimized(decnum):
    wb = Workbook(optimized_write=True)
    ws = wb.create_sheet()
    ws.append([float(decnum)])
    filepath = get_filepath('unoptimized')
    wb.save(filepath)
    return filepath


def readnum(filepath):
    wb = load_workbook(filepath)
    ws = wb.get_active_sheet()
    val = ws.rows[0][0].value
    print val
    return val


def assert_equal(expected, actual):
    assert expected == actual, 'Expected %r, got %r' % (expected, actual)

def assert_float_equal(expected, actual):
    assert_equal(type(expected), type(actual))
    assert_equal(expected, actual)

if __name__ == '__main__':
    input_ = 80.0
    assert_float_equal(input_, readnum(optimized(input_)))
    assert_float_equal(input_, readnum(unoptimized(input_)))

requirements.failing.txt

ipdb==0.8
ipython==2.4.1
jdcal==1.0
lxml==3.3.4
openpyxl==2.1.0
py==1.4.26
pytest==2.5.2

requirements.working.txt

ipdb==0.8
ipython==2.4.1
jdcal==1.0
lxml==3.3.4
openpyxl==2.0.5
py==1.4.26
pytest==2.5.2