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Import-Csv

Updated: May 8, 2014

Applies To: Windows PowerShell 4.0

Import-Csv

Creates table-like custom objects from the items in a CSV file.

Aliases

The following abbreviations are aliases for this cmdlet:

  • ipcsv

Syntax

Parameter Set: Delimiter
Import-Csv [[-Path] <String[]> ] [[-Delimiter] <Char> ] [-Encoding <String> ] [-Header <String[]> ] [-LiteralPath <String[]> ] [ <CommonParameters>]

Parameter Set: UseCulture
Import-Csv [[-Path] <String[]> ] -UseCulture [-Encoding <String> ] [-Header <String[]> ] [-LiteralPath <String[]> ] [ <CommonParameters>]




Detailed Description

The Import-Csv cmdlet creates table-like custom objects from the items in CSV files. Each column in the CSV file becomes a property of the custom object and the items in rows become the property values. Import-Csv works on any CSV file, including files that are generated by the Export-Csv cmdlet.

You can use the parameters of the Import-Csv cmdlet to specify the column header row and the item delimiter, or direct Import-Csv to use the list separator for the current culture as the item delimiter.

You can also use the ConvertTo-Csv and ConvertFrom-Csv cmdlets to convert objects to CSV strings (and back). These cmdlets are the same as the Export-CSV and Import-Csv cmdlets, except that they do not deal with files.

Beginning in Windows PowerShell 3.0, if a header row entry in a CSV file contains an empty or null value, Windows PowerShell inserts a default header row name and displays a warning message. In previous versions of Windows PowerShell, if a header row entry in a CSV file contains an empty or null value, the Import-Csv command fails.

Parameters

-Delimiter<Char>

Specifies the delimiter that separates the property values in the CSV file. The default is a comma (,). Enter a character, such as a colon (:). To specify a semicolon (;), enclose it in quotation marks.

If you specify a character other than the actual string delimiter in the file, Import-Csv cannot create objects from the CSV strings. Instead, it returns the strings.


Aliases

none

Required?

false

Position?

2

Default Value

"," (Comma)

Accept Pipeline Input?

false

Accept Wildcard Characters?

false

-Encoding<String>

Specifies the type of character encoding that was used in the CSV file. Valid values are Unicode, UTF7, UTF8, ASCII, UTF32, BigEndianUnicode, Default, and OEM. The default is ASCII.

This parameter is introduced in Windows PowerShell 3.0.


Aliases

none

Required?

false

Position?

named

Default Value

ASCII

Accept Pipeline Input?

false

Accept Wildcard Characters?

false

-Header<String[]>

Specifies an alternate column header row for the imported file. The column header determines the names of the properties of the object that Import-Csv creates.

Enter a comma-separated list of the column headers. Enclose each item in quotation marks (single or double). Do not enclose the header string in quotation marks. If you enter fewer column headers than there are columns, the remaining columns will have no header. If you enter more headers than there are columns, the extra headers are ignored.

When using the Header parameter, delete the original header row from the CSV file. Otherwise, Import-Csv creates an extra object from the items in the header row.


Aliases

none

Required?

false

Position?

named

Default Value

none

Accept Pipeline Input?

false

Accept Wildcard Characters?

false

-Path<String[]>

Specifies the path to the CSV file to import. You can also pipe a path to Import-Csv.


Aliases

PSPath

Required?

false

Position?

1

Default Value

None

Accept Pipeline Input?

true (ByValue)

Accept Wildcard Characters?

false

-UseCulture

Use the list separator for the current culture as the item delimiter. The default is a comma (,).

To find the list separator for a culture, use the following command: (Get-Culture).TextInfo.ListSeparator. If you specify a character other than the delimiter used in the CSV strings, ConvertFrom-CSV cannot create objects from the CSV strings. Instead, it returns the strings.


Aliases

none

Required?

true

Position?

named

Default Value

"," (Comma)

Accept Pipeline Input?

false

Accept Wildcard Characters?

false

-LiteralPath<String[]>

Specifies the path to the CSV file to import. Unlike Path, the value of the LiteralPath parameter is used exactly as it is typed. No characters are interpreted as wildcards. If the path includes escape characters, enclose it in single quotation marks. Single quotation marks tell Windows PowerShell not to interpret any characters as escape sequences.


Aliases

none

Required?

false

Position?

named

Default Value

none

Accept Pipeline Input?

true (ByPropertyName)

Accept Wildcard Characters?

false

<CommonParameters>

This cmdlet supports the common parameters: -Verbose, -Debug, -ErrorAction, -ErrorVariable, -OutBuffer, and -OutVariable. For more information, see  about_CommonParameters (http://go.microsoft.com/fwlink/p/?LinkID=113216).

Inputs

The input type is the type of the objects that you can pipe to the cmdlet.

  • System.String

    You can pipe a string that contains a path to Import-Csv.


Outputs

The output type is the type of the objects that the cmdlet emits.

  • Object.

    Import-Csv returns the objects described by the content in the CSV file.


Notes

  • Because the imported objects are CSV versions of the object type, they are not recognized and formatted by the Windows PowerShell type formatting entries that format the non-CSV versions of the object type.

  • The result of an Import-Csv command is a collection of strings that form a table-like custom object. Each row is a separate string, so you can use the Count property of the object to count the table rows. The columns are the properties of the object and items in the rows are the property values.

    The column header row determines the number of columns and the column names. The column names are also the names of the properties of the objects. The first row is interpreted to be the column headers, unless you use the Header parameter to specify column headers. If any row has more values than the header row, the additional values are ignored.

    If the column header row is missing a value or contains a null or empty value, Import-Csv uses "H" followed by a number for the missing column header and property name.

    In the CSV file, each object is represented by a comma-separated list of the property values of the object. The property values are converted to strings (by using the ToString() method of the object), so they are generally represented by the name of the property value. Export-CSV does not export the methods of the object.

Examples

-------------------------- EXAMPLE 1 --------------------------

This example shows how to export and then import a CSV file of objects.


 

This example shows how to export and then import a CSV file of objects.

The first command uses the Get-Process cmdlet to get the process on the local computer. It uses a pipeline operator (|) to send the process objects to the Export-CSV cmdlet, which exports the process objects to the Processes.csv file in the current directory.


PS C:\> get-process | export-csv processes.csv

 

The second command uses the Import-Csv cmdlet to import the processes in the Import-Csv file. Then it saves the resulting process objects in the $p variable.


PS C:\>$p = Import-Csv processes.csv

 

The third command uses a pipeline operator to pipe the imported objects to the Get-Member cmdlets. The result shows that they are CSV:System.Diagnostic.Process objects, not the System.Diagnostic.Process objects that Get-Process returns.

Also, because there is no entry type in the formatting files for the CSV version of the process objects, these objects are not formatted in the same way that standard process objects are formatted.

To display the objects, use the formatting cmdlets, such as Format-Table and Format-List, or pipe the objects to Out-GridView.


PS C:\>$p | get-member
TypeName: CSV:System.Diagnostics.Process
Name MemberType Definition
---- ---------- ----------
Equals Method System.Boolean Equals(Object obj)
GetHashCode Method System.Int32 GetHashCode()
GetType Method System.Type GetType()
ToString Method System.String ToString()
BasePriority NoteProperty System.String BasePriority=8
Company NoteProperty System.String Company=Microsoft Corporation
...
PS C:\>$p | out-gridview

-------------------------- EXAMPLE 2 --------------------------

This example shows how to use the Delimiter parameter of the Import-Csv cmdlet. In this example, the processes are exported to a file that uses a colon (:) as a delimiter.

When importing, the Import-Csv file uses the Delimiter parameter to indicate the delimiter that is used in the file.


PS C:\> get-process | export-csv processes.csv -Delimiter :
PS C:\>$p = Import-Csv processes.csv -Delimiter :

-------------------------- EXAMPLE 3 --------------------------

This example shows how to use the UseCulture parameter of the Import-Csv cmdlet.

The first command imports the objects in the Processes.csv file into the $p variable. It uses the UseCulture parameter to direct Import-Csv to use the list separator defined for the current culture.

The second command displays the list separator for the current culture. It uses the Get-Culture cmdlet to get the current culture. It uses the dot (.) method to get the TextInfo property of the current culture and the ListSeparator property of the object in TextInfo. In this example, the command returns a comma.


PS C:\> $p = Import-Csv processes.csv -UseCulture
PS C:\>(get-culture).textinfo.listseparator
,

-------------------------- EXAMPLE 4 --------------------------

This example shows how to use the Header parameter of Import-Csv to change the names of properties in the resulting imported object.


 

The first command uses the Start-Job cmdlet to start a background job that runs a Get-Process command on the local computer. A pipeline operator (|) sends the resulting job object to the Export-CSV cmdlet, which converts the job object to CSV format. An assignment operator (=) saves the resulting CSV in the Jobs.csv file.


PS C:\> start-job -scriptblock { get-process } | export-csv jobs.csv

 

The second command saves a header in the $header variable. Unlike the default header, this header uses "MoreData" instead of "HasMoreData" and "State" instead of "JobStateInfo".


PS C:\>$header = "MoreData","StatusMessage","Location","Command","State","Finished","InstanceId","SessionId","Name","ChildJobs","Output","Error","Progress","Verbose","Debug","Warning","StateChanged"

 

The next three commands delete the original header (the second line) from the Jobs.csv file.


PS C:\> # Delete header from file

PS C:\>$a = (get-content jobs.csv)
PS C:\>$a = $a[0], $a[2..($a.count - 1)]
PS C:\>$a > jobs.csv

 

The sixth command uses the Import-Csv cmdlet to import the Jobs.csv file and convert the CSV strings into a CSV version of the job object. The command uses the Header parameter to submit the alternate header. The results are stored in the $j variable.


PS C:\>$j = Import-Csv jobs.csv -header $header

 

The seventh command displays the object in the $j variable. The resulting object has "MoreData" and "State" properties, as shown in the command output.


                
MoreData : True
StatusMessage :
Location : localhost
Command : get-process
State : Running
Finished : System.Threading.ManualResetEvent
InstanceId : 135bdd25-40d6-4a20-bd68-05282a59abd6
SessionId : 1
Name : Job1
ChildJobs : System.Collections.Generic.List`1[System.Management.Automation.Job]
Output : System.Management.Automation.PSDataCollection`1[System.Management.Automation.PSObject]
Error : System.Management.Automation.PSDataCollection`1[System.Management.Automation.ErrorRecord]
Progress : System.Management.Automation.PSDataCollection`1[System.Management.Automation.ProgressRecord]
Verbose : System.Management.Automation.PSDataCollection`1[System.String]
Debug : System.Management.Automation.PSDataCollection`1[System.String]
Warning : System.Management.Automation.PSDataCollection`1[System.String]
StateChanged :

-------------------------- EXAMPLE 5 --------------------------

This example shows how to create a custom object in Windows PowerShell by using a CSV file.


 

The first command uses the Get-Content cmdlet to get the Links.csv file.


PS C:\> Get-Content .\Links.csv
113207,about_Aliases113208,about_Arithmetic_Operators113209,about_Arrays113210,about_Assignment_Operators113212, 
about_Automatic_Variables113213,about_Break113214,about_Command_Precedence113215,about_Command_Syntax144309,
about_Comment_Based_Help113216,about_CommonParameters113217,about_Comparison_Operators113218,about_Continue113219,
about_Core_Commands113220,about_Data_Section…

 

The second command uses the Import-Csv cmdlet to import the Links.csv file. The command uses the Header parameter to specify LinkId and TopicTitle as property names for the new custom objects. The command saves the imported objects in the $a variable.


PS C:\> $a = Import-Csv -Path .\Links.csv -Header LinkID, TopicTitle

 

The third command uses the Get-Member cmdlet to get the type and members of the custom objects in the $a variable.

The output shows that Import-Csv returns a collection of custom objects (PSCustomObject). In addition to some default properties, the custom objects have LinkID and TopicTitle note properties.


PS C:\> $a | Get-Member
   TypeName: System.Management.Automation.PSCustomObject
Name MemberType Definition
---- ---------- ----------
Equals Method bool
Equals(System.Object obj)
GetHashCode Method int
GetHashCode()GetType Method type
GetType()ToString Method string
ToString()LinkID NoteProperty System.String
LinkID=113207TopicTitle NoteProperty System.String
TopicTitle=about_Aliases

 

This command shows that you can use the custom object like you would any object in Windows PowerShell.

The command pipes the custom objects in the $a variable to the Where-Object cmdlet, which gets only objects with a TopicTitle property that includes "alias".

The Where-Object command uses the new simplified command format that does not require symbols, script blocks, or curly braces.


PS C:\> $a | Where-Object TopicTitle -like "*alias*"
LinkID            TopicTitle
------ ----------
113207 about_Aliases
113432 Alias Provider
113296 Export-Alias
113306 Get-Alias
113339 Import-Alias
113352 New-Alias
113390 Set-Alias

-------------------------- EXAMPLE 6 --------------------------

This example shows how the Import-Csv cmdlet in Windows PowerShell 3.0 responds when the header row in a CSV file includes a null or empty value. Import-Csv substitutes a default name for the header row. The default name becomes the name of the property of the object that Import-Csv returns.


 

The first command uses the Get-Content cmdlet to get the Projects.csv file on the Server02 remote computer. The output shows that the header row of the file is missing a value between "ProjectName" and "Completed."


PS C:\> Get-Content "\\Server2\c$\Test\Projects.csv"
ProjectID, ProjectName,,Completed13, Inventory, Redmond, True440, , FarEast, True469, Marketing, Europe, False

 

The second command uses the Import-Csv cmdlet to import the Projects.csv file.

The output shows that Import-Csv generates a warning and substitutes a default name, H1, for the missing header row value. H1 is also used for the name of the object property.


PS C:\> Import-Csv "\\Server2\c$\Test\Projects.csv"
PS C:\>WARNING: One or more headers were not specified. Default names starting with "H" have been used in place of any missing headers. 
ProjectID ProjectName H1 Completed
--------- ----------- -- ---------
13 Inventory Redmond True
440 FarEast True
469 Marketing Europe False

 

The third command uses the dot method to get the value of the H1 property of the object that Import-Csv creates.


PS C:\> (Import-Csv "\\Server2\c$\Test\Projects.csv").H1
RedmondFarEastEurope

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