使用JavaScript在CSV中计算行数 [英] Count number of lines in CSV with Javascript

问题描述

我想用一种方法计算一个.csv文件中的行数，使用Javascript，任何有用的提示或资源，有人可以指示我。

I'm trying to think of a way to count the number of lines in a .csv file using Javascript, any useful tips or resources someone can direct me to?

推荐答案

取决于你的意思是一行。对于简单数量的换行符，Robusto的回答很好。

Depends what you mean by a line. For simple number of newlines, Robusto's answer is fine.

如果你想知道表示多少个CSV数据行，更困难一点，因为CSV字段本身可以包含换行符：

If you want to know how many rows of CSV data that represents, things may be a little more difficult, as a CSV field may itself contain a newline:

field1,"field
two",field3

...是一行，至少在 RFC4180 。 （这是CSV的一个恶劣的功能，有这么多非标准的变体; RFC本身是非常晚的游戏。）

...is one row, at least in CSV as defined by RFC4180. (It's one of the aggravating features of CSV that there are so many non-standard variants; the RFC itself was very late to the game.)

所以，如果你需要

字段可以是raw，或者（如果它包含 \\\
或，）引用，字段将是：

A field can be raw, or (necessarily if it contains \n or ,) quoted, with " represented as double quotes. So a regex for one field would be:

"([^"]|"")*"|[^,\n]*

，因此对于整行（假设它不为空）：

and so for a whole row (assuming it is not empty):

("([^"]|"")*"|[^,\n]*)(,("([^"]|"")*"|[^,\n]*))*\n

获取其中的数字：

var rowsn= csv.match(/(?:"(?:[^"]|"")*"|[^,\n]*)(?:,(?:"(?:[^"]|"")*"|[^,\n]*))*\n/g).length;

如果你足够幸运地处理符合RFC4180建议的CSV变体，在非引用字段中没有字符，您可以使它更具可读性。在之前换行符计算每行中的字符。如果是偶数，你有一条完整的线;如果它是一个奇数，你有一个拆分。

If you are lucky enough to be dealing with a variant of CSV that complies with RFC4180's recommendation that there are no " characters in unquoted fields, you can make this a bit more readable. Split on newlines as before and count the number of " characters in each line. If it's an even number, you have a complete line; if it's an odd number you've got a split.

var lines= csv.split('\n');
for (var i= lines.length; i-->0;)
    if (lines[i].match(/"/g).length%2===1)
        lines.splice(i-1, 2, lines[i-1]+lines[i]);
var rowsn= lines.length;

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