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[英]How to fetch Value from Excel cell with formula ? Openpyxl data_Only flag doesn't work properly
[英]Read Excel cell value and not the formula computing it -openpyxl
我正在使用 openpyxl 读取单元格值(excel addin-webservice 更新此列。)
我使用data_only = True
但它没有显示当前单元格值,而是 Excel 上次读取工作表时存储的值。
wbFile = openpyxl.load_workbook(filename = xxxx,data_only=True)
wsFile = wbFile[c_sSheet]
如何读取单元格实际值?
wb = openpyxl.load_workbook(filename, data_only=True)
data_only
标志有帮助。
正如@alex-martelli 所说,openpyxl 不评估公式。 当您使用 openpyxl 打开 Excel 文件时,您可以选择读取公式或最后计算的值。 如果如您所指,公式依赖于加载项,则缓存值永远不会准确。 作为文件规范之外的加载项,它们将永远不受支持。 相反,您可能想查看可以与 Excel 运行时交互的xlwings之类的东西。
data_only :甚至为公式单元格读取值。
keep_vba:仅在您使用启用宏的 excel 时使用
file_location = 'C:\Arpan Saini\Monsters\Project_Testing\SecCardGrad\SecCardGrad_Latest_docs\Derived_Test_Cases_Secure_Card_Graduate.xlsm'
wb = load_workbook(file_location, keep_vba=True, data_only=True)
正如@Charlie Clark 提到的,您可以使用xlwings
(如果您有 MS Excel)。 这里有一个例子
假设你有一个带有公式的 Excel 表,例如我用openpyxl
定义一个
from openpyxl import Workbook, load_workbook
wb=Workbook()
ws1=wb['Sheet']
ws1['A1']='a'
ws1['A2']='b'
ws1['A3']='c'
ws1['B1']=1
ws1['B2']=2
ws1['B3']='=B1+B2'
wb.save('to_erase.xlsx')
如前所述,如果我们再次使用openpyxl
加载 excel,我们将不会得到计算公式
wb2 = load_workbook(filename='to_erase.xlsx',data_only=True)
wb2['Sheet']['B3'].value
您可以使用xlwings
来获取由 excel 评估的公式:
import xlwings as xw
wbxl=xw.Book('to_erase.xlsx')
wbxl.sheets['Sheet'].range('B3').value
它返回 3,即预期值。
在处理具有非常复杂的公式和工作表之间引用的电子表格时,我发现它非常有用。
面临同样的问题。 无论这些单元格是什么,都需要读取单元格值:标量、具有预先计算值的公式或没有它们的公式,容错性优于正确性。
该策略非常简单:
pycel
对其进行评估;pycel
对公式的有限支持或有一些错误),警告并返回 None。我创建了一个隐藏所有这些机制的类,并为读取单元格值提供了简单的接口。
如果正确性优于容错性,则很容易修改类,以便在第 4 步引发异常。
希望它会帮助某人。
from traceback import format_exc
from pathlib import Path
from openpyxl import load_workbook
from pycel.excelcompiler import ExcelCompiler
import logging
class MESSAGES:
CANT_EVALUATE_CELL = ("Couldn't evaluate cell {address}."
" Try to load and save xlsx file.")
class XLSXReader:
"""
Provides (almost) universal interface to read xlsx file cell values.
For formulae, tries to get their precomputed values or, if none,
to evaluate them.
"""
# Interface.
def __init__(self, path: Path):
self.__path = path
self.__book = load_workbook(self.__path, data_only=False)
def get_cell_value(self, address: str, sheet: str = None):
# If no sheet given, work with active one.
if sheet is None:
sheet = self.__book.active.title
# If cell doesn't contain a formula, return cell value.
if not self.__cell_contains_formula(address, sheet):
return self.__get_as_is(address, sheet)
# If cell contains formula:
# If there's precomputed value of the cell, return it.
precomputed_value = self.__get_precomputed(address, sheet)
if precomputed_value is not None:
return precomputed_value
# If not, try to compute its value from the formula and return it.
# If failed, report an error and return empty value.
try:
computed_value = self.__compute(address, sheet)
except:
logging.warning(MESSAGES.CANT_EVALUATE_CELL
.format(address=address))
logging.debug(format_exc())
return None
return computed_value
# Private part.
def __cell_contains_formula(self, address, sheet):
cell = self.__book[sheet][address]
return cell.data_type is cell.TYPE_FORMULA
def __get_as_is(self, address, sheet):
# Return cell value.
return self.__book[sheet][address].value
def __get_precomputed(self, address, sheet):
# If the sheet is not loaded yet, load it.
if not hasattr(self, '__book_with_precomputed_values'):
self.__book_with_precomputed_values = load_workbook(
self.__path, data_only=True)
# Return precomputed value.
return self.__book_with_precomputed_values[sheet][address].value
def __compute(self, address, sheet):
# If the computation engine is not created yet, create it.
if not hasattr(self, '__formulae_calculator'):
self.__formulae_calculator = ExcelCompiler(self.__path)
# Compute cell value.
computation_graph = self.__formulae_calculator.gen_graph(
address, sheet=sheet)
return computation_graph.evaluate(f"{sheet}!{address}")
我通过以下方式解决了这个问题:
import xlwings
from openpyxl import load_workbook
data = load_workbook('PATH_TO_YOUR_XLSX_FILE')
data['sheet_name']['A1'].value = 1
data.save('PATH_TO_YOUR_XLSX_FILE')
excel_app = xlwings.App(visible=False)
excel_book = excel_app.books.open('PATH_TO_YOUR_XLSX_FILE')
excel_book.save()
excel_book.close()
excel_app.quit()
data = load_workbook('PATH_TO_YOUR_XLSX_FILE', data_only=True)
我希望,这可以帮助你...
如果有“REF!”,我发现 data_only 选项无法正常工作。 工作表中的错误单元格。 Openpyxl 为我的小测试 xlsx 文件中的每个单元格值返回 None 。 对我来说,在打开 Excel 并修复单元格后,data_only 可以完美运行。 我使用 openpyxl 3.0.3
我没有使用 Python 库来进行 Excel 计算,而是让 Excel 来进行计算。
为什么? 它不是纯 Python,但它最大限度地减少了涉及的 Python 数量。 我没有使用 Python 来评估 Excel 公式,而是让 Excel 处理它自己的功能。 这避免了评估 Excel 公式的 Python 中任何可能的错误。 以下概述了这种方法的工作原理:
这是一个 Windows 测试程序,它创建一个新工作簿,将公式“=SUM(Al:C3)”放入单元格 E2,将数据放入单元格 A1-C3,然后计算公式。
from openpyxl import load_workbook, Workbook
from pynput.keyboard import Key, Controller
import subprocess
import time
import os
excel_prog = r'C:\Program Files\Microsoft Office\root\Office16\EXCEL.EXE'
# Create test Excel workbook, get default worksheet.
wb = Workbook()
ws = wb.active
# Put data and a formula into worksheet.
for row_index in range(1,4):
for column_index in range(1,4):
ws.cell(row = row_index, column = column_index).value = row_index + column_index
ws['E1'].value = 'Sum of cells in range A1:C3:'
ws['E2'].value = '=SUM(A1:C3)'
# Try to get value of formula. We'll see the formula instead.
print('E2:', ws['E2'].value)
# Save and close workbook.
wb.save(filename = 'test.xlsx')
wb.close()
# Pause to give workbook time to close.
time.sleep(5)
# Open the workbook in Excel. I specify folder, otherwise Excel will
# open in "Protected View", interfering with using pynput.
subprocess.Popen([excel_prog, os.path.join(os.getcwd(), 'test.xlsx')])
# Pause to give workbook time to open and for formulas to update.
time.sleep(5)
# Save workbook using pynput.
keyboard = Controller()
with keyboard.pressed(Key.ctrl):
keyboard.press('s')
keyboard.release('s')
# Pause to give workbook time to save.
time.sleep(5)
# Close workbook.
with keyboard.pressed(Key.alt):
keyboard.press(Key.f4)
keyboard.release(Key.f4)
# Pause to give workbook time to fully close.
time.sleep(5)
# Open Excel workbook and worksheet in openpyxl, data-only.
wb = load_workbook(filename = 'test.xlsx', data_only = True)
ws = wb.active
# Get value of the cell containing the formula.
print('E2:', ws['E2'].value)
# Close workbook.
wb.close()
在 openpyxl 上,使用 xlwings。
Xlcalculator具有评估单元格的能力。
from xlcalculator import ModelCompiler
from xlcalculator import Model
from xlcalculator import Evaluator
filename = r'xxxx.xlsm'
compiler = ModelCompiler()
new_model = compiler.read_and_parse_archive(filename)
evaluator = Evaluator(new_model)
val1 = evaluator.evaluate('First!A2')
print("value 'evaluated' for First!A2:", val1)
输出是:
First!A2 的“评估”值:0.1
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