读取Excel单元格值而不是计算它的公式-openpyxl

Question

我正在使用openpyxl来读取单元格值(excel addin-webservice更新此列.)

我已经使用data_only = True但它没有显示当前单元格值,而是它是上次Excel读取工作表时存储的值.

wbFile = openpyxl.load_workbook(filename = xxxx,data_only=True)
wsFile = wbFile[c_sSheet]

我如何读取单元格的实际值？

Answer 1

wb = openpyxl.load_workbook(filename, data_only=True)

该data_only标志帮助.

Answer 2

正如@ alex-martelli所说,openpyxl不会评估公式.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.如果您指出,公式依赖于加载项,则缓存的值永远不会准确.作为文件规范之外的加载项,它们永远不会受到支持.相反,您可能希望查看可以与Excel运行时交互的xlwings之类的内容.

Answer 3

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

假设您有一个带有公式的 Excel 表，例如我定义了一个 openpyxl

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，如果我们再次加载 excel openpyxl，我们将不会得到评估公式

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。

我发现它在处理具有非常复杂的公式和工作表之间的引用的电子表格时非常有用。

Answer 4

data_only ：读取甚至公式单元格的值。

keep_vba：仅当您使用启用宏的 excel 时才使用它

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)

Answer 5

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...

Answer 6

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、带有预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：

1. 如果单元格不包含公式，则返回单元格的值；
2. 如果是公式，则尝试获取其预先计算的值；
3. 如果不能，请尝试使用pycel;
4. 如果失败（由于对pycel公式的支持有限或有一些错误），警告并返回 None。

我创建了一个类，它隐藏了所有这些机制，并提供了用于读取单元格值的简单界面。

如果正确性优于容错性，则可以轻松修改该类，以便在第 4 步时引发异常。

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}")