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SQLDBAWithABeard/weird.ipynb

Last active January 30, 2020 21:19
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strange behaviour in PowerShell Notebook with function and comment code
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weird.ipynb
{
"metadata": {
"kernelspec": {
"name": "powershell",
"display_name": "PowerShell"
},
"language_info": {
"name": "powershell",
"codemirror_mode": "shell",
"mimetype": "text/x-sh",
"file_extension": ".ps1"
}
},
"nbformat_minor": 2,
"nbformat": 4,
"cells": [
{
"cell_type": "markdown",
"source": [
"The original code with the Functions defined and a comment at the end of the function definition\r\n",
"\r\n",
"**doesnt work** - means that when you try to run the cell it just sits spinning"
],
"metadata": {
"azdata_cell_guid": "22132f5d-8b78-4164-8771-f9f2453a5f12"
}
},
{
"cell_type": "code",
"source": [
"Function Get-LuhnChecksum {\n",
" <#\n",
" .SYNOPSIS\n",
" Calculates Luhn Checksum of a number\n",
" .DESCRIPTION\n",
" Uses the Luhn Algorighm to calculate the checksum of a number\n",
" .EXAMPLE\n",
" Get-LuhnChecksum -Number 111\n",
" (Returns a Luhn Checksum of 5)\n",
" .NOTES\n",
" Further reading: https://en.wikipedia.org/wiki/Luhn_algorithm\n",
" #>\n",
" param (\n",
" # Value to calculate Luhn digit from\n",
" [Parameter(Mandatory=$true)] [long] $Number\n",
" )\n",
" if($Number -lt 0) {throw \"Value cannot be negative.\"}\n",
" # convert to array of digits\n",
" $digits = [byte[]](($Number -split '') -ne '')\n",
" # From the rightmost digit, and moving left, double the value of this and every second digit.\n",
" # If the result of doubling is greater than 9, then add the digits together. (eg 7*2 = 14, 1+4=5).\n",
" # An equivalent operation to adding the digits is to subtract 9. (eg 7*2 = 14, 14-9 = 5).\n",
" # is the rightmost digit even or odd? Each digit matching is doubled.\n",
" $checkModValue = ($digits.Count - 1) % 2\n",
" for ($i = $digits.Count - 1; $i -ge 0; $i--) {\n",
" if($i % 2 -eq $checkModValue) {\n",
" $digits[$i] = $digits[$i] * 2\n",
" if ($digits[$i] -gt 9) {\n",
" $digits[$i] = $digits[$i] - 9\n",
" }\n",
" }\n",
" }\n",
" # Sum all the digits.\n",
" $sum = 0\n",
" $digits | ForEach-Object {$sum += $_}\n",
" # Multiply the sum by 9, and take the ones digit (modulo 10) to find the Luhn digit.\n",
" $LuhnDigit = ($sum * 9) % 10\n",
" [PSCustomObject]@{\n",
" \"Original Number\" = $Number\n",
" \"Luhn Checksum\" = $LuhnDigit\n",
" }\n",
"}# Get-LuhnChecksum\n",
"Function Test-LuhnChecksum {\n",
" <#\n",
" .SYNOPSIS\n",
" Validates a number containing a Luhn Checksum\n",
" .DESCRIPTION\n",
" Uses the Luhn Algorighm to validate a number containing a Luhn Checksum\n",
" .EXAMPLE\n",
" Test-LuhnChecksum -Number 1115\n",
" (Returns that the number is valid)\n",
" .EXAMPLE\n",
" Test-LuhnChecksum -Number 1114\n",
" (Returns that the number is not valid)\n",
" .NOTES\n",
" Further reading: https://en.wikipedia.org/wiki/Luhn_algorithm\n",
" #>\n",
" param (\n",
" # Value to validate via Luhn Checksum\n",
" [Parameter(Mandatory=$true)] [long] $Number\n",
" )\n",
" if($Number -lt 0) {throw \"Value cannot be negative.\"}\n",
" # separate checksum digit from rest of number\n",
" $NumberString = $Number.ToString()\n",
" $LuhnDigit = [convert]::ToByte($NumberString.Substring($NumberString.Length-1,1))\n",
" $NumberWithoutLuhn = [convert]::ToInt64($NumberString.Substring(0, $NumberString.Length-1))\n",
" $o = Get-LuhnChecksum -Number $NumberWithoutLuhn\n",
" [PSCustomObject]@{\n",
" \"Value\" = $Number\n",
" \"IsValid\" = $o.\"Luhn Checksum\" -eq $LuhnDigit\n",
" }\n",
"}# Test-LuhnChecksum"
],
"metadata": {
"azdata_cell_guid": "38d8092a-10de-4224-9b50-83f6324c85bc"
},
"outputs": [],
"execution_count": 0
},
{
"cell_type": "markdown",
"source": [
"Take it back to basics and it does work"
],
"metadata": {
"azdata_cell_guid": "442cbc3f-fa84-4786-92b8-c4481bf0f0dc"
}
},
{
"cell_type": "code",
"source": [
"Function Get-LuhnChecksum {\r\n",
"\r\n",
"}\r\n",
"Function Test-LuhnChecksum {\r\n",
" \r\n",
"}"
],
"metadata": {
"azdata_cell_guid": "e461d0e0-5a09-4836-ab87-9c14f72a33b0"
},
"outputs": [
{
"output_type": "stream",
"name": "stdout",
"text": ""
}
],
"execution_count": 1
},
{
"cell_type": "markdown",
"source": [
"Add in the comment and it doesnt work"
],
"metadata": {
"azdata_cell_guid": "fdf7ceef-9e99-4e7c-b542-368c34c9df7d"
}
},
{
"cell_type": "code",
"source": [
"Function Get-LuhnChecksum {\r\n",
" \r\n",
"}# Get-LuhnChecksum\r\n",
"Function Test-LuhnChecksum {\r\n",
" \r\n",
"}# Test-LuhnChecksum"
],
"metadata": {
"azdata_cell_guid": "9a714d67-5a61-42cc-8a61-8d52d6913752"
},
"outputs": [],
"execution_count": 0
},
{
"cell_type": "markdown",
"source": [
"Just to check - All of the code without the comment does work"
],
"metadata": {
"azdata_cell_guid": "3366bfbc-88bc-401b-aff0-64a19088000d"
}
},
{
"cell_type": "code",
"source": [
"Function Get-LuhnChecksum {\r\n",
" <#\r\n",
" .SYNOPSIS\r\n",
" Calculates Luhn Checksum of a number\r\n",
" .DESCRIPTION\r\n",
" Uses the Luhn Algorighm to calculate the checksum of a number\r\n",
" .EXAMPLE\r\n",
" Get-LuhnChecksum -Number 111\r\n",
" (Returns a Luhn Checksum of 5)\r\n",
" .NOTES\r\n",
" Further reading: https://en.wikipedia.org/wiki/Luhn_algorithm\r\n",
" #>\r\n",
" param (\r\n",
" # Value to calculate Luhn digit from\r\n",
" [Parameter(Mandatory=$true)] [long] $Number\r\n",
" )\r\n",
" if($Number -lt 0) {throw \"Value cannot be negative.\"}\r\n",
" # convert to array of digits\r\n",
" $digits = [byte[]](($Number -split '') -ne '')\r\n",
" # From the rightmost digit, and moving left, double the value of this and every second digit.\r\n",
" # If the result of doubling is greater than 9, then add the digits together. (eg 7*2 = 14, 1+4=5).\r\n",
" # An equivalent operation to adding the digits is to subtract 9. (eg 7*2 = 14, 14-9 = 5).\r\n",
" # is the rightmost digit even or odd? Each digit matching is doubled.\r\n",
" $checkModValue = ($digits.Count - 1) % 2\r\n",
" for ($i = $digits.Count - 1; $i -ge 0; $i--) {\r\n",
" if($i % 2 -eq $checkModValue) {\r\n",
" $digits[$i] = $digits[$i] * 2\r\n",
" if ($digits[$i] -gt 9) {\r\n",
" $digits[$i] = $digits[$i] - 9\r\n",
" }\r\n",
" }\r\n",
" }\r\n",
" # Sum all the digits.\r\n",
" $sum = 0\r\n",
" $digits | ForEach-Object {$sum += $_}\r\n",
" # Multiply the sum by 9, and take the ones digit (modulo 10) to find the Luhn digit.\r\n",
" $LuhnDigit = ($sum * 9) % 10\r\n",
" [PSCustomObject]@{\r\n",
" \"Original Number\" = $Number\r\n",
" \"Luhn Checksum\" = $LuhnDigit\r\n",
" }\r\n",
"}\r\n",
"Function Test-LuhnChecksum {\r\n",
" <#\r\n",
" .SYNOPSIS\r\n",
" Validates a number containing a Luhn Checksum\r\n",
" .DESCRIPTION\r\n",
" Uses the Luhn Algorighm to validate a number containing a Luhn Checksum\r\n",
" .EXAMPLE\r\n",
" Test-LuhnChecksum -Number 1115\r\n",
" (Returns that the number is valid)\r\n",
" .EXAMPLE\r\n",
" Test-LuhnChecksum -Number 1114\r\n",
" (Returns that the number is not valid)\r\n",
" .NOTES\r\n",
" Further reading: https://en.wikipedia.org/wiki/Luhn_algorithm\r\n",
" #>\r\n",
" param (\r\n",
" # Value to validate via Luhn Checksum\r\n",
" [Parameter(Mandatory=$true)] [long] $Number\r\n",
" )\r\n",
" if($Number -lt 0) {throw \"Value cannot be negative.\"}\r\n",
" # separate checksum digit from rest of number\r\n",
" $NumberString = $Number.ToString()\r\n",
" $LuhnDigit = [convert]::ToByte($NumberString.Substring($NumberString.Length-1,1))\r\n",
" $NumberWithoutLuhn = [convert]::ToInt64($NumberString.Substring(0, $NumberString.Length-1))\r\n",
" $o = Get-LuhnChecksum -Number $NumberWithoutLuhn\r\n",
" [PSCustomObject]@{\r\n",
" \"Value\" = $Number\r\n",
" \"IsValid\" = $o.\"Luhn Checksum\" -eq $LuhnDigit\r\n",
" }\r\n",
"}"
],
"metadata": {
"azdata_cell_guid": "b7e6506b-2d63-4907-8c05-a8c1e3f6ed23"
},
"outputs": [
{
"output_type": "stream",
"name": "stdout",
"text": ""
}
],
"execution_count": 1
},
{
"cell_type": "markdown",
"source": [
"Add a space after the } doesnt work"
],
"metadata": {
"azdata_cell_guid": "d353385c-72c4-4449-8ff1-c810550c273d"
}
},
{
"cell_type": "code",
"source": [
"Function Get-LuhnChecksum {\r\n",
" \r\n",
"} # Get-LuhnChecksum\r\n",
"Function Test-LuhnChecksum {\r\n",
"\r\n",
"} # Test-LuhnChecksum"
],
"metadata": {
"azdata_cell_guid": "a0acae4c-870e-4b96-94da-7f8897a49a8d"
},
"outputs": [],
"execution_count": 0
},
{
"cell_type": "markdown",
"source": [
"Put the comment on its own line also doesnt work"
],
"metadata": {
"azdata_cell_guid": "c972ce86-146d-412d-96ed-4fd6fc440a3e"
}
},
{
"cell_type": "code",
"source": [
"Function Get-LuhnChecksum {\r\n",
" \r\n",
"}\r\n",
"\r\n",
"# Get-LuhnChecksum\r\n",
"\r\n",
"Function Test-LuhnChecksum {\r\n",
" \r\n",
"}\r\n",
"\r\n",
"# Test-LuhnChecksum"
],
"metadata": {
"azdata_cell_guid": "007f228f-c449-46e4-ad5c-50ef5e1333f7"
},
"outputs": [],
"execution_count": 0
},
{
"cell_type": "markdown",
"source": [
"Use <# #> for the comment - does work"
],
"metadata": {
"azdata_cell_guid": "2a933040-640a-4265-8deb-47d6f1d267f2"
}
},
{
"cell_type": "code",
"source": [
"Function Get-LuhnChecksum {\n",
" \n",
"}\n",
"\n",
" <# Get-LuhnChecksum #>\n",
"Function Test-LuhnChecksum {\n",
" \n",
"}\n",
"\n",
"<# Test-LuhnChecksum #>"
],
"metadata": {
"azdata_cell_guid": "74f0704c-e005-4624-9a44-e782272cdff9"
},
"outputs": [
{
"name": "stdout",
"text": "",
"output_type": "stream"
}
],
"execution_count": 1
},
{
"cell_type": "markdown",
"source": [
""
],
"metadata": {
"azdata_cell_guid": "01a58c7c-096e-4990-9827-77adf44fad10"
}
}
]
}
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