I'm working in powershell with an imported CSV. I have a data set like this:
ID First_Name Last_Nam
-- ---------- --------
2314 Kenny Anderson
21588 Mark Anderson
2547 Ben Andrews
5797 Benjamin Armour
Except with 2000 people and many more columns. Currently the data is stored as a series of hashes in a #{ID = "..",First_Name:"..",Last_Name:".."} and these are stored in a System Object array. I want to store each hash as an index in an array. I want to get the hashtable at that index, but I don't know how to into the System.Object Array. Here's my code:
$csv = import-csv $csv_name
$row = #(0)*csv.length
$hash = #{}
for($i =0; $i -lt $csv.length; $i++){
$row[$i] += $csv[$i]
}
#error: cannot convert "#{ID : "..", First_Name: "..", Last_Name:".." to Systems.Int32
for($i =0; $i -lt $csv.length; $i++){
$csv[$i].psobject.properties | Foreach { $hash[$_.Name] = $_.Value }
$row[$i]+=$hash
}
#error: Cannot convert systems.collections.hashtable into Systems.Int32
I'm looking for a way to index the array so I can get the hashtable at that index. the The first one, with pointers to the hashtables accessible through the array, is what I think would be the easiest to manipulate. If there's an easier way to get a specific hashtable just from the System.Object[] itself, please tell me.
I should add I don't know the names or amount of the columns in advance.
The return value of Import-Csv is not an array of [hashtable]s, it's an array of [psobject]s, where each column is a property.
There's no need to build any kind of array to get an individual object by index.
$csv = import-csv $csv_name
$csv[0]
$csv[1].First_Name
# etc
The errors in your code have nothing to do with the question you posed though; you're getting errors trying to add objects to an array, because you're actually trying to add an object or hashtable to an existing array element of type integer.
You don't need to precreate the array with a bunch of zeros, so this line isn't needed:
$row = #(0)*csv.length
Instead, you can create an empty array:
$row = #()
Then, you can just add to the array itself:
$row += $hash
Related
I have one array of hashtables like the one below:
$hashtable1 = #{}
$hashtable1.name = "aaa"
$hashtable1.surname =#()
$hashtable1.surname += "bbb"
$hashtable2 = #{}
$hashtable2.name = "aaa"
$hashtable2.surname =#()
$hashtable2.surname += "ccc"
$hashtable3 = #{}
$hashtable3.name = "bbb"
$hashtable3.surname = #()
$hashtable3.surname += "xxx"
$A = #($hashtable1; $hashtable2; $hashtable3)
I need to iterate though the array and I need to find out duplicates based on hashtable[].name
Then I need to group those hashtable.surname to hashtable[].surname so that the result will be an array of hashtables that will group all for name all the surnames:
$hashtable1.name = "aaa"
$hashtable1.surname = ("bbb","ccc")
$hashtable3.name = "bbb"
$hashtable3.surname = ("xxx")
I was looking into iterating to empty array
+
I have found this link:
powershell compare 2 arrays output if match
but I am not sure on how to reach into the elements of the hashtable.
My options:
I was wondering if -contain can do it.
I have read about compare-object but I am not sure it can be done like that.
(It looks a bit scary in the moment)
I am on PS5.
Thanks for your help,
Aster
You can group your array items by the names using a scriptblock like so.
Once grouped, you can easily build your output to do what you seek.
#In PS 7.0+ you can use Name directly but earlier version requires the use of the scriptblock when dealing with arrays of hashtables.
$Output = $A | Group-Object -Property {$_.Name} | % {
[PSCustomObject]#{
Name = $_.Name
Surname = $_.Group.Surname | Sort-Object -Unique
}
}
Here is the output variable content.
Name Surname
---- -------
aaa {bbb, ccc}
bbb xxx
Note
Improvements have been made in PS 7.0 that allows you to use simply the property name (eg: Name) in Group-Object for arrays of hashtables, just like you would do for any other arrays type. For earlier version though, these particular arrays must be accessed by passing the property in a scriptblock, like so: {$_.Name}
References
MSDN - Group_Object
SS64 - Group Object
Dr Scripto - Use a Script block to create custom groupings in PowerShell
I've got multiple pairs of Arrays.
The first of the pair contains multiple strings.
The second contains a timestamp belonging to the string at the same position of the first array.
Here are two pairs of arrays for an example:
#String array
M681
T9997
E61
H717
K700
#Timestamp Array
11:00
11:05
11:05
11:10
11:15
The second pair of Arrays would look like this:
#String array
B722
T732
L999
M681
I125
#Timestamp Array
11:00
11:00
11:05
11:10
11:15
I want to find matches where a string is in two pairs and then i want to measure the time difference between both entries.
Comparing the string-arrays was simply done by (Compare-Object -IncludeEqual -ReferenceObject $a_string -DifferenceObject $b_string -ExcludeDifferent).InputObject, but with this i couldnt compare the responding timestamps.
So my next idea was forging each pair together in a hashtable:
$hash = #{}
$hash.Add($a_string[$i],$a_timestamp[$i])
But i noticed that this would not work in my enviroment since both the strings and the timestamps could reoccur in one array, so setting one of them as the key of the hash would not be possible.
Next I tried creating a hashtable with an array as value and an index as key:
$hash.Add($indexNumber,#($a_string[$i],$a_timestamp[$i]))
Even though $hash.indexNumber prints out both values, i cant seem to get on of the values by $hash.indexNumber[0] / $hash.indexNumber[1]
I would appreciate if someone could tell me the best practice with this kind of situation or could tell me how I can successfully get the seperate Values of the array inside the hash and compare them to other array values in different hashes.
Kind regards,
Paxz.
So this is a relatively naive solution and will probably need some work to properly handle edge cases, but hopefully it will get you going in the right direction:
$arrayNames1 = #('M681','T9997','E61','H717','K700')
$arrayTimes1 = #('11:00','11:05','11:05','11:10','11:15')
$arrayNames2 = #('B722','T732','L999','M681','I125')
$arrayTimes2 = #('11:00','11:00','11:05','11:10','11:15')
function Find-AllIndexesOf{
param(
$array,
$term
)
$i = 0
foreach($item in $array){
if($item -eq $term){
$i
}
$i++
}
}
foreach($name in $arrayNames1){
if($arrayNames2.Contains($name)){
$array1Locations = Find-AllIndexesOf $arrayNames1 $name
$array2Locations = Find-AllIndexesOf $arrayNames2 $name
$i = 0
foreach($location in $array1Locations){
$thisTime1 = [datetime]$arrayTimes1[$array1Locations]
$thisTime2 = [datetime]$arrayTimes2[$array2Locations[$i]]
Write-Host ('I found a time difference for {0} that started at {1} and ended at {2} for {3} total minutes' -f $name, $thisTime1, $thisTime2, ($thisTime2 - $thisTime1).TotalMinutes)
$i++
}
}
}
But i noticed that this would not work in my enviroment since both the strings and the timestamps could reoccur in one array, so setting one of them as the key of the hash would not be possible.
I am unclear on why a simple hashtable does not work in your use case.
$table = #{}
for ($i = 0; $i -lt $a_string.count; $i++){
if(!$table.Contains($a_string[$i])){
$table.Add($a_string[$i], #())
$table[$a_string[$i]] += $a_timestamp[$i]
}else{
$table[$a_string[$i]] += $a_timestamp[$i]
}
}
This would generate a table mapped with Strings to times which could then be used to compare against other pairs.
I'm at a bit of a loss to understand why this code isn't doing what I think it should.
This is part of a larger plan but in essence I'm attempting to fill part of an array with entries from a text file, though I've replaced that bit with a hard coded array. The end result is the same.
$users = 12345,23456,34567,45678,56789,67890
$a = New-Object PSCustomObject
$a = $a|Select ID
$collection = #()
$users|%{
$a.ID = $_
$collection += $a
}
$collection|ft -a
This outputs the following:
ID
--
67890
67890
67890
67890
67890
67890
If you output the array to screen as it gets built, you can watch the values get replaced each time with the most recent entry.
What's the fault? Is there something unusual with the way I'm initialising the $a variable or the array?
It's doing that because there is only one object ($a), and all your loop is doing is changing the value of the one property (ID), and adding another reference to it to the array.
You need to create a new object for each cycle of the loop:
$users = 12345,23456,34567,45678,56789,67890
$a = New-Object PSCustomObject
$a = $a|Select ID
$collection = #()
$users|%{
$a = New-Object PSCustomObject
$a = $a|Select ID
$a.ID = $_
$collection += $a
}
$collection|ft -a
PS is adding a reference to the object itself into the array, rather than the object contents at the time it's added. Changing the value of $a.ID at any point changes the contents displayed by $collection.
To fix this, you can move the initialization for $a within the % statement like so:
$users = 12345,23456,34567,45678,56789,67890
$collection = #()
$users|%{
$a = New-Object PSCustomObject
$a = $a|Select ID
$a.ID = $_
$collection += $a
}
$collection|ft -a
or just simply add $a.ID to $collection if you only want the ID value in that array.
Not quite sure what you're trying to accomplish here, really... but what if you try it like this?
$collection += $a.ID
You create one object ($a). You then add this one object to $collection multiple times. Each time you add it you change its .ID property value. So at the end you have $collection holding many copies of this one object. So you get many copies of that one ID value. Create a new object each time inside the loop if you want multiple objects with different values.
After reading this helpful article on the Windows PowerShell Blog, I realized I could "shift" off the first part of an array, but didn't know how to "unshift" or push elements onto the front of an array in PowerShell.
I am creating an array of hash objects, with the last read item pushed onto the array first. I'm wondering if there is a better way to accomplish this.
## Create a list of files for this collection, pushing item on top of all other items
if ($csvfiles[$collname]) {
$csvfiles[$collname] = #{ repdate = $date; fileobj = $csv }, $csvfiles[$collname] | %{$_}
}
else {
$csvfiles[$collname] = #{ repdate = $date; fileobj = $csv }
}
A couple of things to note:
I need to unroll the previous array element with a foreach loop %{$_}, because merely referencing the array would create a nested array structure. I have to have all the elements at the same level.
I need to differentiate between an empty array and one that contains elements. If I attempt to unroll an empty array, it places a $null element at the end of the array.
Thoughts?
PS: The reason the empty hash element produces a NULL value is that $null is treated as a scalar in PowerShell. For details, see https://connect.microsoft.com/PowerShell/feedback/details/281908/foreach-should-not-execute-the-loop-body-for-a-scalar-value-of-null.
ANSWER:
Looks like the best solution is to pre-create the empty array when necessary, rather than code around the $null issue. Here's the rewrite using a .NET ArrayList and a native PoSh array.
if (!$csvfiles.ContainsKey($collname)) {
$csvfiles[$collname] = [System.Collections.ArrayList]#()
}
$csvfiles[$collname].insert(0, #{ repdate = $repdate; fileobj = $csv })
## NATIVE POSH SOLUTION...
if (!$csvfiles.ContainsKey($collname)) {
$csvfiles[$collname] = #()
}
$csvfiles[$collname] = #{ repdate = $repdate; fileobj = $csv }, `
$csvfiles[$collname] | %{$_}
You might want to use ArrayList objects instead, as they support insertions at arbitrary locations. For example:
# C:\> $a = [System.Collections.ArrayList]#(1,2,3,4)
# C:\> $a.insert(0,6)
# C:\> $a
6
1
2
3
4
You can simply use a plus operator:
$array = #('bar', 'baz')
$array = #('foo') + $array
Note: this re-creates actually creates a new array instead of changing the existing one (but the $head, $tail = $array way of shifting you refer to works extactly in the same way).
How can I put $org into an array together with $count?
Like this example array:
$myArray = #{
1="SampleOrg";
2="AnotherSampleOrg"
}
Another example:
$myArray = #{
$count="$org";
$count="$org"
}
Example foreach:
$count=0;get-organization | foreach {$count++; $org = $_.Name.ToString();write-host $count -nonewline;write-host " $org"}
$answer = read-host "Select 1-$count"
The above will display:
1 SampleOrg
2 AnotherSampleOrg
Select 1-2:
What I would like to do afterwards is to put the array to use in a switch.
Example:
switch ($answer)
{
1 {$org=myArray[1]} #<-- or whatever that corresponds to "SampleOrg"
2 {$org=myArray[2]} #<-- or whatever that corresponds to "AnotherSampleOrg"
}
You have to initialize your hashtable somewhere before the loop:
$myArray = #{}
and add a
$myArray.Add($count, $org)
to your foreach-loop.
EDIT: For the discussion about hastable/array see the whole thread ;) I just kept the name of the variable from the original posting
Looks like you're confusing arrays and Hashtables. Arrays are ordered, and indexed by an numeric value. Hashtables are associative, and indexed by any value that has equality defined.
This is array syntax
$arr = #(1,2,3)
and this is Hashtable syntax
$ht = #{red=1;blue=2;}
For your question, the following will work
$orgs = #(get-organization | % { $_.Name })
this will create a 0 based array, mapping int -> OrgName, so
$orgs[$answer]
will get the correct name. Or if you're using 1 based indexing
$orgs[$answer-1]
Note, I removed the switch, as there's no reason for it.