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Python:将实例变量传递给类方法

xlsxwriter python-2.7 python

toti08 · 技术社区 · 7 年前

我正在使用 xlsxwriter 我创建了一个类,在其中我创建了一个工作簿。然后我添加了2个工作表。现在我已经编写了一个方法,将数据写入其中一个工作表,但现在我想在两个工作表上都使用它。这是一个简单的例子来解释这种情况:

import xlsxwriter

class ExcelWorkbook():
    def __init__(self, filename):
        self.wb = xlsxwriter.Workbook(filename)
        self.ws1 = self.wb.add_worksheet('Num')
        self.ws1LineCount = 0
        self.ws2 = self.wb.add_worksheet('Result')
        self.ws2LineCount = 0

    def write_data(self, data, title):        
        self.ws1.write_row(self.ws1LineCount, 0, title)
        self.ws1LineCount += 1
        self.ws1.write_row(self.ws1LineCount, 0, data)
        self.ws1LineCount += 1

xlsxWorkbook = ExcelWorkbook('Test2.xlsx')
numArr = (0.000000520593523979187, 13.123456789, 1.789456, 0.002345, 0.00123, 1)
titleBar = ('Date', 'quantity', 'Average [m]', 'Standard Dev [m]', 'Test', 'Success')
xlsxWorkbook.write_data(numArr, titleBar)

write_data 方法,所以我想将工作表作为参数传递,但不幸的是,它并没有那么简单,因为我无法传递实例变量 self.ws1 或 self.ws2 .

所以问题是:我该怎么做?

我想出了一个非常糟糕的解决方案,比如:

def write_data(self, data, title, instance = 'ws1'):
    if instance == 'ws1':
        instance = self.ws1
        lineCounter = self.ws1LineCount
    elif instance == 'ws2':
        instance = self.ws2
        lineCounter = self.ws2LineCount

    instance.write_row(self.ws1LineCount, 0, title)
    lineCounter += 1
    instance.write_row(self.ws1LineCount, 0, data)
    lineCounter += 1

但老实说,我不喜欢它。有没有一个合适的方法来做这件事,或者这是一件完全不合理的事情?

4 回复 | 直到 7 年前

buran 7 年前

与其使用if块,不如使用 workbook.get_worksheet_by_name() 方法

def write_data(self, data, title, ws = 'Num'):
    wsheet = self.wb.get_worksheet_by_name(ws)
    wsheet.write_row(self.ws1LineCount, 0, title)
    lineCounter += 1
    wsheet.write_row(self.ws1LineCount, 0, data)
    lineCounter += 1

编辑:也可以使用getattr()函数,例如。

def write_data(self, data, title, ws = 'ws1'):
    wsheet = getattr(self, ws, self.ws1))
    wsheet.write_row(self.ws1LineCount, 0, title)
    lineCounter += 1
    wsheet.write_row(self.ws1LineCount, 0, data)
    lineCounter += 1

Felix 7 年前

from collections import defaultdict
import xlsxwriter

class ExcelWorkbook():
    def __init__(self, filename):
        self.wb = xlsxwriter.Workbook(filename)

        self.ws1 = self.wb.add_worksheet('Num')
        self.ws2 = self.wb.add_worksheet('Result')
        self._line_counts = defaultdict(int)

    def write_data(self, ws, data, title):
        self._write_row(ws, title)
        self._write_row(ws, data)

    def _write_row(self, ws, content):
        ws.write_row(self._line_counts[ws], 0, content)
        self._line_counts[ws] += 1

xlsxWorkbook = ExcelWorkbook('Test2.xlsx')
numArr = (0.000000520593523979187, 13.123456789, 1.789456, 0.002345, 0.00123, 1)
titleBar = ('Date', 'quantity', 'Average [m]', 'Standard Dev [m]', 'Test', 'Success')
xlsxWorkbook.write_data(xlsxWorkbook.ws1, numArr, titleBar)
xlsxWorkbook.write_data(xlsxWorkbook.ws2, numArr, titleBar)

利用 defaultdict ,您不需要为每个工作表显式保留行计数变量。这个 write_data 函数接受一个新参数 ws 以便您可以设置应写入的工作表。可以将行写入单独的方法中,以减少代码重复。

这回答了你的问题吗?

编辑:

self ,但您可以非常轻松地解决此问题:

def write_data(self, data, title, ws=None):
        if ws is None:            
            ws = self.ws1
        self._write_row(ws, title)
        self._write_row(ws, data)

Cartucho Vasyl 7 年前

也许你应该考虑多上一节课 ExcelWorksheet ,以便将所有与它们相关的逻辑放入:

class ExcelWorksheet(object):
    def __init__(self, workbook, name):
        self.wb = workbook
        self.ws = self.wb.add_worksheet(name)
        self.wsLineCount = 0

    def write_data(self, data, title):        
        self.ws.write_row(self.wsLineCount, 0, title)
        self.wsLineCount += 1
        self.ws.write_row(self.wsLineCount, 0, data)
        self.wsLineCount += 1

通过这种方式,您可以将代码重构为:

class ExcelWorkbook(object):
    def __init__(self, filename):
        self.wb = xlsxwriter.Workbook(filename)
        self.ws1 = ExcelWorksheet(self.wb, 'Num')
        self.ws2 = ExcelWorksheet(self.wb, 'Result')


xlsxWorkbook = ExcelWorkbook('Test2.xlsx')
numArr = (0.000000520593523979187, 13.123456789, 1.789456, 0.002345, 0.00123, 1)
titleBar = ('Date', 'quantity', 'Average [m]', 'Standard Dev [m]', 'Test', 'Success')
xlsxWorkbook.ws1.write_data(numArr, titleBar)
xlsxWorkbook.ws2.write_data(numArr, titleBar)

-1

Vince 7 年前

然后vars(self)[“ws1”]类似于self.ws1,vars(self)[“ws2”]类似于self.ws2

然后只需在write_数据中传递一个关键参数“ws1”或“ws2”。

def write_data(self, data, title, key='ws1'):
    instance = vars(self)[key]
    lineCounter = vars(self)[key+"LineCount"]

    instance.write_row(lineCounter , 0, title)
    lineCounter += 1
    instance.write_row(lineCounter , 0, data)
    lineCounter += 1