我制作了一个脚本,每隔几个小时就会向 Google Apps 电子表格添加一个新行。
这是我用来查找第一个空行的函数:
function getFirstEmptyRow() {
var spr = SpreadsheetApp.getActiveSpreadsheet();
var cell = spr.getRange('a1');
var ct = 0;
while ( cell.offset(ct, 0).getValue() != "" ) {
ct++;
}
return (ct);
}
它工作正常,但是当达到大约 100 行时,它变得非常慢,甚至 10 秒。
我担心当达到数千行时,它会太慢,可能会超时或更糟。
有没有更好的办法?
最佳答案
这个问题现在已经不止 12K 次观看 - 是时候更新了,因为新工作表的性能特征与 Serge ran his initial tests 时不同.
好消息:性能要好得多!
最快的:
与第一次测试一样,只读取一次工作表的数据,然后对数组进行操作,就带来了巨大的性能优势。有趣的是,Don 的原始函数性能比 Serge 测试的修改版本要好得多。 (似乎 while
比 for
快,这不合逻辑。)
样本数据的平均执行时间仅为 38 毫秒 , 低于之前的 168ms .
// Don's array approach - checks first column only
// With added stopping condition & correct result.
// From answer https://stackoverflow.com/a/9102463/1677912
function getFirstEmptyRowByColumnArray() {
var spr = SpreadsheetApp.getActiveSpreadsheet();
var column = spr.getRange('A:A');
var values = column.getValues(); // get all data in one call
var ct = 0;
while ( values[ct] && values[ct][0] != "" ) {
ct++;
}
return (ct+1);
}
检测结果:
以下是结果,在一个 100 行 x 3 列的电子表格中总结了超过 50 次迭代(填充了 Serge 的测试函数)。
函数名称与下面脚本中的代码相匹配。
“第一个空行”
最初的要求是找到第一个空行。以前的脚本都没有真正实现这一点。许多人只检查一列,这意味着他们可能会给出假阳性结果。其他人只找到跟随所有数据的第一行,这意味着会遗漏非连续数据中的空行。
这是一个符合规范的函数。它被包含在测试中,虽然比闪电般快速的单列检查器慢,但它以 68 毫秒的速度出现,比正确答案高 50%!
/**
* Mogsdad's "whole row" checker.
*/
function getFirstEmptyRowWholeRow() {
var sheet = SpreadsheetApp.getActiveSheet();
var range = sheet.getDataRange();
var values = range.getValues();
var row = 0;
for (var row=0; row<values.length; row++) {
if (!values[row].join("")) break;
}
return (row+1);
}
完整脚本:
如果您想重复测试,或将您自己的函数添加到组合中作为比较,只需获取整个脚本并在电子表格中使用它。
/**
* Set up a menu option for ease of use.
*/
function onOpen() {
var menuEntries = [ {name: "Fill sheet", functionName: "fillSheet"},
{name: "test getFirstEmptyRow", functionName: "testTime"}
];
var sh = SpreadsheetApp.getActiveSpreadsheet();
sh.addMenu("run tests",menuEntries);
}
/**
* Test an array of functions, timing execution of each over multiple iterations.
* Produce stats from the collected data, and present in a "Results" sheet.
*/
function testTime() {
var ss = SpreadsheetApp.getActiveSpreadsheet();
ss.getSheets()[0].activate();
var iterations = parseInt(Browser.inputBox("Enter # of iterations, min 2:")) || 2;
var functions = ["getFirstEmptyRowByOffset", "getFirstEmptyRowByColumnArray", "getFirstEmptyRowByCell","getFirstEmptyRowUsingArray", "getFirstEmptyRowWholeRow"]
var results = [["Iteration"].concat(functions)];
for (var i=1; i<=iterations; i++) {
var row = [i];
for (var fn=0; fn<functions.length; fn++) {
var starttime = new Date().getTime();
eval(functions[fn]+"()");
var endtime = new Date().getTime();
row.push(endtime-starttime);
}
results.push(row);
}
Browser.msgBox('Test complete - see Results sheet');
var resultSheet = SpreadsheetApp.getActive().getSheetByName("Results");
if (!resultSheet) {
resultSheet = SpreadsheetApp.getActive().insertSheet("Results");
}
else {
resultSheet.activate();
resultSheet.clearContents();
}
resultSheet.getRange(1, 1, results.length, results[0].length).setValues(results);
// Add statistical calculations
var row = results.length+1;
var rangeA1 = "B2:B"+results.length;
resultSheet.getRange(row, 1, 3, 1).setValues([["Avg"],["Stddev"],["Trimmed\nMean"]]);
var formulas = resultSheet.getRange(row, 2, 3, 1);
formulas.setFormulas(
[[ "=AVERAGE("+rangeA1+")" ],
[ "=STDEV("+rangeA1+")" ],
[ "=AVERAGEIFS("+rangeA1+","+rangeA1+',"<"&B$'+row+"+3*B$"+(row+1)+","+rangeA1+',">"&B$'+row+"-3*B$"+(row+1)+")" ]]);
formulas.setNumberFormat("##########.");
for (var col=3; col<=results[0].length;col++) {
formulas.copyTo(resultSheet.getRange(row, col))
}
// Format for readability
for (var col=1;col<=results[0].length;col++) {
resultSheet.autoResizeColumn(col)
}
}
// Omiod's original function. Checks first column only
// Modified to give correct result.
// question https://stackoverflow.com/questions/6882104
function getFirstEmptyRowByOffset() {
var spr = SpreadsheetApp.getActiveSpreadsheet();
var cell = spr.getRange('a1');
var ct = 0;
while ( cell.offset(ct, 0).getValue() != "" ) {
ct++;
}
return (ct+1);
}
// Don's array approach - checks first column only.
// With added stopping condition & correct result.
// From answer https://stackoverflow.com/a/9102463/1677912
function getFirstEmptyRowByColumnArray() {
var spr = SpreadsheetApp.getActiveSpreadsheet();
var column = spr.getRange('A:A');
var values = column.getValues(); // get all data in one call
var ct = 0;
while ( values[ct] && values[ct][0] != "" ) {
ct++;
}
return (ct+1);
}
// Serge's getFirstEmptyRow, adapted from Omiod's, but
// using getCell instead of offset. Checks first column only.
// Modified to give correct result.
// From answer https://stackoverflow.com/a/18319032/1677912
function getFirstEmptyRowByCell() {
var spr = SpreadsheetApp.getActiveSpreadsheet();
var ran = spr.getRange('A:A');
var arr = [];
for (var i=1; i<=ran.getLastRow(); i++){
if(!ran.getCell(i,1).getValue()){
break;
}
}
return i;
}
// Serges's adaptation of Don's array answer. Checks first column only.
// Modified to give correct result.
// From answer https://stackoverflow.com/a/18319032/1677912
function getFirstEmptyRowUsingArray() {
var sh = SpreadsheetApp.getActiveSpreadsheet();
var ss = sh.getActiveSheet();
var data = ss.getDataRange().getValues();
for(var n=0; n<data.length ; n++){
if(data[n][0]==''){n++;break}
}
return n+1;
}
/**
* Mogsdad's "whole row" checker.
*/
function getFirstEmptyRowWholeRow() {
var sheet = SpreadsheetApp.getActiveSheet();
var range = sheet.getDataRange();
var values = range.getValues();
var row = 0;
for (var row=0; row<values.length; row++) {
if (!values[row].join("")) break;
}
return (row+1);
}
function fillSheet(){
var sh = SpreadsheetApp.getActiveSpreadsheet();
var ss = sh.getActiveSheet();
for(var r=1;r<1000;++r){
ss.appendRow(['filling values',r,'not important']);
}
}
// Function to test the value returned by each contender.
// Use fillSheet() first, then blank out random rows and
// compare results in debugger.
function compareResults() {
var a = getFirstEmptyRowByOffset(),
b = getFirstEmptyRowByColumnArray(),
c = getFirstEmptyRowByCell(),
d = getFirstEmptyRowUsingArray(),
e = getFirstEmptyRowWholeRow(),
f = getFirstEmptyRowWholeRow2();
debugger;
}
关于performance - 在 Google Sheet 列中查找第一个空行的更快方法,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/6882104/