问题
I am sorry if this question as been asked before, but I couldn't find anything similar.
I am receiving CSV output that uses " as a text qualifier around every field. I am looking for an elegant solution to reformat these so that only specific (alphanumeric fields) have these qualifiers.
An example of what I am receiving:
"TRI-MOUNTAIN/MOUNTAI","F258273","41016053","A","10/16/14",3,"1","Recruit-Navy,XL#28-75","13.25","13.25"
My desired output would be this:
"TRI-MOUNTAIN/MOUNTAI","F258273",41016053,"A",10/16/14,3,1,"Recruit-Navy,XL#28-75",13.25,13.25
Any suggestions or assistance are greatly appreciated!
Per request below find the first five lines of the example file:
"TRI-MOUNTAIN/MOUNTAI","F258273","41016053","","10/16/14","","1","Recruit-Navy,XL#28-75","13.25","13.25"
"TRI-MOUNTAIN/MOUNTAI","F258273","41016053","","10/16/14","","1","High Peak-Navy,XL#21-18","36.75","36.75"
"TRI-MOUNTAIN/MOUNTAI","F257186","Z1023384","","10/15/14","","1","Patriot-Red,L#26-35","25.50","25.50"
"TRI-MOUNTAIN/MOUNTAI","F260780","Z1023658","","10/20/14","","1","Exeter-Red/Gray,S#23-52","19.75","19.75"
"TRI-MOUNTAIN/MOUNTAI","F260780","Z1023658","","10/20/14","","1","Exeter-White/Gray,XL#23-56","19.75","19.75"
Note that this is only an example and not all files will be for Tri-Mountain.
回答1:
Since you've not specified OS or language, here is the PowerShell version.
I've ditched my previous attempt to work with Import-CSV because of your non-standard CSV files and switched to raw file processing. Should be significantly faster too.
Regex to split CSV is from this question: How to split a string by comma ignoring comma in double quotes
Save this script as StripQuotes.ps1. It accepts following arguments:
- InPath: folder to read CSVs from. If not specified, the current directory is used.
- OutPath: folder to save processed CSVs to. Will be created, if not exist.
- Encoding: If not specified, script will use system's current ANSI code page to read the files. You can get other valid encodings for your system in PowerShell console like this:
[System.Text.Encoding]::GetEncodings() - Verbose: script will tell you what's going on via
Write-Verbosemessages.
Example (run from the PowerShell console).
Process all CSVs in the folder C:\CSVs_are_here, save processed CSVs to the folder C:\Processed_CSVs, be verbose:
.\StripQuotes.ps1 -InPath 'C:\CSVs_are_here' -OutPath 'C:\Processed_CSVs' -Verbose
StripQuotes.ps1 script:
Param
(
[Parameter(ValueFromPipelineByPropertyName = $true)]
[ValidateScript({
if(!(Test-Path -LiteralPath $_ -PathType Container))
{
throw "Input folder doesn't exist: $_"
}
$true
})]
[ValidateNotNullOrEmpty()]
[string]$InPath = (Get-Location -PSProvider FileSystem).Path,
[Parameter(Mandatory = $true, ValueFromPipelineByPropertyName = $true)]
[ValidateScript({
if(!(Test-Path -LiteralPath $_ -PathType Container))
{
try
{
New-Item -ItemType Directory -Path $_ -Force
}
catch
{
throw "Can't create output folder: $_"
}
}
$true
})]
[ValidateNotNullOrEmpty()]
[string]$OutPath,
[Parameter(ValueFromPipelineByPropertyName = $true)]
[string]$Encoding = 'Default'
)
if($Encoding -eq 'Default')
{
# Set default encoding
$FileEncoding = [System.Text.Encoding]::Default
}
else
{
# Try to set user-specified encoding
try
{
$FileEncoding = [System.Text.Encoding]::GetEncoding($Encoding)
}
catch
{
throw "Not valid encoding: $Encoding"
}
}
$DQuotes = '"'
$Separator = ','
# https://stackoverflow.com/questions/15927291/how-to-split-a-string-by-comma-ignoring-comma-in-double-quotes
$SplitRegex = "$Separator(?=(?:[^$DQuotes]|$DQuotes[^$DQuotes]*$DQuotes)*$)"
# Matches a single code point in the category "letter".
$AlphaNumRegex = '\p{L}'
Write-Verbose "Input folder: $InPath"
Write-Verbose "Output folder: $OutPath"
# Iterate over each CSV file in the $InPath
Get-ChildItem -LiteralPath $InPath -Filter '*.csv' |
ForEach-Object {
Write-Verbose "Current file: $($_.FullName)"
$InFile = New-Object -TypeName System.IO.StreamReader -ArgumentList (
$_.FullName,
$FileEncoding
) -ErrorAction Stop
Write-Verbose 'Created new StreamReader'
$OutFile = New-Object -TypeName System.IO.StreamWriter -ArgumentList (
(Join-Path -Path $OutPath -ChildPath $_.Name),
$false,
$FileEncoding
) -ErrorAction Stop
Write-Verbose 'Created new StreamWriter'
Write-Verbose 'Processing file...'
while(($line = $InFile.ReadLine()) -ne $null)
{
$tmp = $line -split $SplitRegex |
ForEach-Object {
# Strip double quotes, if any
$item = $_.Trim($DQuotes)
if($_ -match $AlphaNumRegex)
{
# If field has at least one letter - wrap in quotes
$DQuotes + $item + $DQuotes
}
else
{
# Else, pass it as is
$item
}
}
# Write line to the new CSV file
$OutFile.WriteLine($tmp -join $Separator)
}
Write-Verbose "Finished processing file: $($_.FullName)"
Write-Verbose "Processed file is saved as: $($OutFile.BaseStream.Name)"
# Close open files and cleanup objects
$OutFile.Flush()
$OutFile.Close()
$OutFile.Dispose()
$InFile.Close()
$InFile.Dispose()
}
回答2:
This problem presents the difficulty of separating quotes from comma separated fields where the fields themselves contain embedded commas. (e.g.: "Recruit-Navy,XL#28-75") There are a number of ways to approach this from a shell standpoint (while read, awk, etc.) but most will ultimately stumble on the embedded comma.
One approach found to be successful was a brute force character-by-character parse of the line. (below) This isn't an elegant solution, but it will get you started. The other alternative to a shell program would be a compiled language, such as C, where character handling is a bit more robust. Leave a comment if you have questions.
#!/bin/bash
declare -a arr
declare -i ct=0
## fill array with separated fields (preserving comma in fields)
# Note: the following is a single-line (w/continuations for readability)
arr=( $( line='"TRI-MOUNTAIN/MOUNTAI","F258273","41016053","A","10/16/14",3,"1","Recruit-Navy,XL#28-75","13.25","13.25"'; \
for ((i=0; i < ${#line}; i++)); do \
if test "${line:i:1}" == ',' ; then \
if test "${line:i+1:1}" == '"' -o "${line:i-1:1}" == '"' ; then \
printf " "; \
else \
printf "%c" ${line:i:1}; \
fi; \
else \
printf "%c" ${line:i:1}; \
fi; \
done; \
printf "\n" ) )
## remove quotes from non-numeric fields
for i in "${arr[@]}"; do
if [[ "${i:0:1}" == '"' ]] && [[ ${i:1:1} == [0123456789] ]]; then
arr[$ct]="${i//\"/}"
else
arr[$ct]="$i"
fi
if test "$ct" -eq 0 ; then
printf "%s" "${arr[ct]}"
else
printf ",%s" "${arr[ct]}"
fi
((ct++))
done
printf "\n"
exit 0
output
$ bash sepquoted.sh
"TRI-MOUNTAIN/MOUNTAI","F258273",41016053,"A",10/16/14,3,1,"Recruit-Navy,XL#28-75",13.25,13.25
original
"TRI-MOUNTAIN/MOUNTAI","F258273","41016053","A","10/16/14",3,"1","Recruit-Navy,XL#28-75","13.25","13.25"
来源：https://stackoverflow.com/questions/28883218/csv-formatting-strip-qualifier-from-specific-fields