Add up the data if the reference from another file is correct - powershell

Question

I have two CSV Files which look like this:
test.csv:
"Col1","Col2"
"1111","1"
"1122","2"
"1111","3"
"1121","2"
"1121","2"
"1133","2"
"1133","2"
The second looks like this:
test2.csv:
"Number","signs"
"1111","ABC"
"1122","DEF"
"1111","ABC"
"1121","ABC"
"1133","GHI"
Now the goal is to get a summary of all points from test.csv assigned to the "signs" of test2.csv. Reference are the numbers, as you may see.
Should be something like this:
ABC = 8
DEF = 2
GHI = 4
I have tried to test this out but cannot get the goal. What I have so far is:
$var = "C:\PathToCSV"
$csv1 = Import-Csv "$var\test.csv"
$csv2 = Import-Csv "$var\test2.csv"
# Process: group by 'Item' then sum 'Average' for each group
# and create output objects on the fly
$test1 = $csv1 | Group-Object Col1 | ForEach-Object {
New-Object psobject -Property #{
Col1 = $_.Name
Sum = ($_.Group | Measure-Object Col2 -Sum).Sum
}
}
But this gives me back the following output:
Ps> $test1
Sum Col1
--- ----
4 1111
2 1122
4 1121
4 1133
I am not able to get the summary and the mapping of the signs.

Answer 1

Not sure if I understand your question correctly, but I'm going to assume that for each value from the column "signs" you want to lookup the values from the column "Number" in the second CSV and then calculate the sum of the column "Col2" for all matches.
For that I'd build a hashtable with the pre-calculated sums for the unique values from "Col1":
$h1 = #{}
$csv1 | ForEach-Object {
$h1[$_.Col1] += [int]$_.Col2
}
and then build a second hashtable to sum up the lookup results for the values from the second CSV:
$h2 = #{}
$csv2 | ForEach-Object {
$h2[$_.signs] += $h1[$_.Number]
}
However, that produced a different value for "ABC" than what you stated as the desired result in your question when I processed your sample data:
Name Value
---- -----
ABC 12
GHI 4
DEF 2
Or did you mean you want to sum up the corresponding values for the unique numbers for each sign? For that you'd change the second code snippet to something like this:
$h2 = #{}
$csv2 | Group-Object signs | ForEach-Object {
$name = $_.Name
$_.Group | Select-Object -Unique -Expand Number | ForEach-Object {
$h2[$name] += $h1[$_]
}
}
That would produce the desired result from your question:
Name Value
---- -----
ABC 8
GHI 4
DEF 2