例子

例子

我想知道是否有一种简单的方法,也许是一个衬垫,使用unix cli工具来沿着定义的时间偏移/中断/差异(例如两个小时)以毫秒精度(+%FT%T.%3NZ例如2021-05-27T13:59:33.641Z)分割带有ISO-8601 UTC时间戳的CSV文件。

一如既往,有某些不同的方式来获得它,而对于有类似问题的其他用户,其他选项也可能与全面的答案相关,我......

  • ...使用/拥有 git 2.31.1's GNU Bash 4.4.23, GNU sed 4.8, GNU Awk 5.0.0(以及它捆绑的所有其他工具),xsv 0.13.0jq 1.6Windows 7 上
  • ...宁愿在交互式 shell 的脚本中使用它
  • ...使用分号 ( ;) 作为分隔符,不使用逗号
  • ... 做不是引用我的值(例如,用单引号 ( ') 或双引号 ( ") 括起来)
  • ...没有标题
  • ...已经将整个 CSV 保存在变量中,并且还希望将结果保存在变量(数组?)中,以便能够进一步分析它们
  • 我的专栏做不是实际上有固定的长度,除了字母数字字符外还可能包含空格和连字符
  • 时间戳是我的现实世界数据中八列中的第五列
  • 可以假设该文件最多为 250k 行和 20 MiB
  • 虽然在我的 i5-4300U 上脚本/命令花费的时间少于半秒会更好,但最多 5 到 10 秒仍然不会破坏交易

例子

如果我有2 hours用于分割的偏移量(并且我没有混淆任何内容),则此文件:

abc;square;2021-05-27T14:15:39.315Z
def;circle;2021-05-27T14:17:03.416Z
ghi;triang;2021-05-27T14:45:13.520Z
abc;circle;2021-05-27T15:25:47.624Z
ghi;square;2021-05-27T17:59:33.641Z
def;triang;2021-05-27T18:15:33.315Z
abc;circle;2021-05-27T21:12:13.350Z
ghi;triang;2021-05-27T21:15:31.135Z

将分为以下三个部分

abc;square;2021-05-27T14:15:39.315Z
def;circle;2021-05-27T14:17:03.416Z
ghi;triang;2021-05-27T14:45:13.520Z
abc;circle;2021-05-27T15:25:47.624Z
ghi;square;2021-05-27T17:59:33.641Z
def;triang;2021-05-27T18:15:33.315Z
abc;circle;2021-05-27T21:12:13.350Z
ghi;triang;2021-05-27T21:15:31.135Z

免责声明:我不是母语人士,所以如果改写使这个问题更容易理解,请继续。冗长的回复。例如,还指定不适用于我的用例(逗号、引号)的选项,或者在这个问题的文本中同时使用单词semicolon和符号是为了 SEO 目的;

答案1

鉴于变量中的示例 CSV 数据$csv

gawk '
    function timestamp2epoch(ts,       m) {
        if(match(ts, /([0-9]{4})-([0-9]{2})-([0-9]{2})T([0-9]{2}):([0-9]{2}):([0-9]{2})\..*/, m)) 
            return mktime(m[1] " " m[2] " " m[3] " " m[4] " " m[5] " " m[6])
        else
            return -1
    }

    BEGIN {
        FS = ";"
        interval = 2 * 3600     # 2 hours
    }

    { t = timestamp2epoch($3) }
    t > start + interval { start = t; n++ }
    { batch[n] = batch[n] (batch[n] == "" ? "" : "/") $0 }

    END {
        PROCINFO["sorted_in"] = "@ind_num_asc"
        for (i in batch)
            print batch[i]
    }
' <<<"$csv"

输出

abc;square;2021-05-27T14:15:39.315Z/def;circle;2021-05-27T14:17:03.416Z/ghi;triang;2021-05-27T14:45:13.520Z/abc;circle;2021-05-27T15:25:47.624Z
ghi;square;2021-05-27T17:59:33.641Z/def;triang;2021-05-27T18:15:33.315Z
abc;circle;2021-05-27T21:12:13.350Z/ghi;triang;2021-05-27T21:15:31.135Z

可以将其读入 shell 数组,例如:

mapfile -t batches < <(gawk '...' <<<"$csv")
declare -p batches
declare -a batches=([0]="abc;square;2021-05-27T14:15:39.315Z/def;circle;2021-05-27T14:17:03.416Z/ghi;triang;2021-05-27T14:45:13.520Z/abc;circle;2021-05-27T15:25:47.624Z" [1]="ghi;square;2021-05-27T17:59:33.641Z/def;triang;2021-05-27T18:15:33.315Z" [2]="abc;circle;2021-05-27T21:12:13.350Z/ghi;triang;2021-05-27T21:15:31.135Z")

然后对它们进行交互,如下所示:

for ((i = 0; i < "${#batches[@]}"; i++)); do
    IFS="/" read -ra records <<<"${batches[i]}"
    echo "batch $i"
    for record in "${records[@]}"; do echo "  $record"; done
    echo
done
batch 0
  abc;square;2021-05-27T14:15:39.315Z
  def;circle;2021-05-27T14:17:03.416Z
  ghi;triang;2021-05-27T14:45:13.520Z
  abc;circle;2021-05-27T15:25:47.624Z

batch 1
  ghi;square;2021-05-27T17:59:33.641Z
  def;triang;2021-05-27T18:15:33.315Z

batch 2
  abc;circle;2021-05-27T21:12:13.350Z
  ghi;triang;2021-05-27T21:15:31.135Z

答案2

以下 perl 脚本将输出输入文件,每次看到不在上一个开始时间段 2 小时内的行时都会添加一个空行 - 将输入分成最长持续时间为 2 小时的批次。

起始时间段在读取第一行时设置,并且仅在打印额外的空白行时更新 - 这是为了确保至少每 2 小时生成一个新批次 - 否则您的样本输入将仅分为两个批次(来自的 6 行) 14:15 到 18:15,以及 21:12 和 21:15 的 2 行),并且在 16:45 处添加一个额外的日志条目,在 20:00 处添加另一个日志条目,这样可以防止样本输入的任何拆分。

它从输入的第三个字段获取日期和时间 - 请注意,perl 数组从零而不是从一开始,$F[2]array 的第三个字段也是如此@F

#!/usr/bin/perl

use strict;
use Date::Parse;

my $start;

while(<>) {
  chomp;
  my $approx;
  my @F = split /;/;

  # approximate date/time to start of hour
  ($approx = $F[2]) =~ s/:\d\d:\d\d\.\d+Z$/:00:00/;

  my $now = str2time($approx);
  $start = $now if ($. == 1);

  if (($now - $start) > 7200) {
    $start = $now;
    print "\n";
  };
  print "$_\n";
}

示例输出:

$ ./split.pl input.csv 
abc;square;2021-05-27T14:15:39.315Z
def;circle;2021-05-27T14:17:03.416Z
ghi;triang;2021-05-27T14:45:13.520Z
abc;circle;2021-05-27T15:25:47.624Z

ghi;square;2021-05-27T17:59:33.641Z
def;triang;2021-05-27T18:15:33.315Z

abc;circle;2021-05-27T21:12:13.350Z
ghi;triang;2021-05-27T21:15:31.135Z

如果您需要在单独的文件中输出,您可以这样做:

#!/usr/bin/perl

use strict;
use Date::Parse;

my $start;

# output-file counter
my $fc = 1;
my $outfile = "file.$fc.csv";

open (my $fh, ">", $outfile) || die "couldn't open $outfile for write: $!\n";

while(<>) {
  chomp;
  my $approx;
  my @F = split /;/;

  # approximate date/time to start of hour
  ($approx = $F[2]) =~ s/:\d\d:\d\d\.\d+Z$/:00:00/;

  my $now = str2time($approx);
  $start = $now if ($. == 1);

  if (($now - $start) > 7200) {
    $start = $now;
    close($fh);
    $fc++;
    $outfile = "file.$fc.csv";
    open ($fh, ">", $outfile) || die "couldn't open $outfile for write: $!\n";
  };
  print $fh "$_\n";
}

如果您希望任一版本的脚本在其可以处理的时间格式方面更加灵活,请使用:

  ($approx = $F[2]) =~ s/:\d\d:\d\d(?:\.\d+)?Z?$/:00:00/;

这允许时间字符串中的小数部分和 Z 都是可选的。

答案3

使用 GNU awk forgensub()mktime()

$ cat tst.awk
BEGIN {
    FS = ";"
    maxSecs = 2 * 60 * 60
    prevTime = -(maxSecs + 1)
}
{
    split($3,dt,/[.]/)
    dateHMS   = gensub(/[-T:]/," ","g",dt[1])
    currSecs  = mktime(dateHMS,1) "." dt[2]
    secsDelta = currTime - prevTime
    prevTime  = currTime
}
secsDelta > maxSecs {
    close(out)
    out = "out" (++numOut)
}
{ print > out }

$ awk -f tst.awk file

$ head out?
==> out1 <==
abc;square;2021-05-27T14:15:39.315Z
def;circle;2021-05-27T14:17:03.416Z
ghi;triang;2021-05-27T14:45:13.520Z
abc;circle;2021-05-27T15:25:47.624Z

==> out2 <==
ghi;square;2021-05-27T17:59:33.641Z
def;triang;2021-05-27T18:15:33.315Z

==> out3 <==
abc;circle;2021-05-27T21:12:13.350Z
ghi;triang;2021-05-27T21:15:31.135Z

答案4

如果文件中的所有日期都属于同一天:

#!/usr/bin/awk -f
BEGIN {
    FS=OFS=";"
    ho = 1
}

{
    # Split the last field in date and times
    split($NF, a, "T")

    # Get the hour from time
    h = a[2]
    sub(/:.*$/, "", h)
    
    if (lh == 0) lh = h+ho

    if (h > lh) {
        lh = h+ho
        print "\n"
    }
}1

您可以编辑脚本块ho中的(小时偏移)BEGIN,以在 csv 中拆分为其他小时偏移。


#!/usr/bin/awk -f
BEGIN {
    FS=OFS=";"

    # Set here the hour offset
    hour_offset = 1

    # Get the hour values in seconds
    ho = 60 * 60 * hour_offset
}

{
    sub(/Z$/, "", $NF)

    # Call /bin/date and translate the 'visual date' to
    # epoch timestamp.
    cmd="/bin/date -d " $NF " +%s"
    epoch=((cmd | getline line) > 0 ? line : -1)
    close(cmd)

    if (epoch == -1) {
        print "Date throw an error at : " NR;
        exit 1; 
    }

    # If the lh (last hour) is not set, set it
    # to the current value for the epoch time plus 
    # the chosen offset
    if (!lh) lh = epoch + ho

    # if the current offset less the the old hour processed is
    # greater then the offset you choose: update the offset and 
    # print the separator
    if (epoch - lh > ho) {
        lh = epoch + ho
        print ""
    }
}1

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