Tag: powershell (Page 4 of 7)

Subtitle: In one line

The other day at work, I had a file of a bunch of activities and the dates on which they occurred.  Something like this:

What I wanted to do was to get a count of the number of activities occurring on each day, so I fired up a PowerShell command shell and ran the following one-liner:

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ipcsv "C:\my_path\test_data.csv"|group event_date|select Name, Count

That line produced these results:

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Name       Count

----       -----

8/23/2018     10

9/19/2018      8

7/3/2018      18

10/13/2018    15

11/2/2018      9

10/1/2018     15

Nice.  I have my counts, but it’d be even better if my dates were in order.  Let’s try to sort those suckers:

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ipcsv "C:\my_path\test_data.csv"|sort event_date|group event_date|select Name, Count

That produced:

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Name       Count

----       -----

10/1/2018     15

10/13/2018    15

11/2/2018      9

7/3/2018      18

8/23/2018     10

9/19/2018      8

Not the kind of sorting I was looking for.  It sorted the dates like they were strings.  Wait a minute…

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PS C:\WINDOWS\system32> (ipcsv "C:\my_path\test_data.csv")[0].event_date.GetType()



IsPublic IsSerial Name                                     BaseType                                                                                                                           

-------- -------- ----                                     --------                                                                                                                           

True     True     String                                   System.Object

Just as I suspected: PowerShell is importing those dates as strings!  If I want to sort my results by date, I’ll have to cast that date to a proper datetime data type first.  Here’s what I came up with:

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ipcsv "C:\my_path\test_data.csv"|select -Property @{Name="event_dt"; Expression={[datetime]$_.event_date}}|sort event_dt|group event_dt|select Name, Count

And the results:

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Name                   Count

----                   -----

7/3/2018 12:00:00 AM      18

8/23/2018 12:00:00 AM     10

9/19/2018 12:00:00 AM      8

10/1/2018 12:00:00 AM     15

10/13/2018 12:00:00 AM    15

11/2/2018 12:00:00 AM      9

Nice!  I generated my counts and sorted by date all in one line of code.  Sweet!

In a couple of previous posts, I proposed a couple of ways to easily copy all or a portion of your music library to a thumb drive for playing in your usb-enabled automobile.  You can check out my solution at my Github page.

Recently, though, I encountered yet another frustration: my “copy” script iterates through a JSON file of the inventory of my music.  In the file, my music is listed in alphabetical order by the artist.  So, I copy my music to my thumb drive in alphabetical order.  Which means I’ll get Aerosmith on my thumb drive, but will likely never get ZZ Top.  Bummer!  So, I came up with a great solution: Get-Random!

All I need to do is alter one line in my “copy” script:

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# apply my selection criteria and get a list of the songs to copy over to the flashdrive

$mp3s_to_write_to_drive = $mp3_col | where {$genres_i_want -contains $_.genre} | where {$bands_to_skip -notcontains $_.artist} | sort {Get-Random}

I just need to pipe my $mp3_col collection object to “sort {Get-Random}”.  This will sort the mp3 files randomly such that they’ll be copied to my thumb drive in a random order.  Cool!

I’ll probably not update my script in Github with this minor change, but just tack this little command at the end of the line in your downloaded copy of the script and you’ll be set.