Import-Csv

Creates table-like custom objects from the items in a CSV file.
Import-Csv [[-Path] [<String[]>]] [[-Delimiter] [<Char>]] [-Encoding {Unicode | UTF7 | UTF8 | ASCII | UTF32 |BigEndianUnicode | Default | OEM}] [-Header [<String[]>]] [-LiteralPath [<String[]>]] [<CommonParameters>]
Import-Csv [[-Path] [<String[]>]] [-Encoding {Unicode | UTF7 | UTF8 | ASCII | UTF32 | BigEndianUnicode | Default |OEM}] [-Header [<String[]>]] [-LiteralPath [<String[]>]] -UseCulture* [<CommonParameters>]

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.

-Encoding [<String>]

Specifies the type of character encoding that was used in the CSV file. The acceptable values for this parameter are:

— Unicode– UTF7– UTF8– ASCII– UTF32– BigEndianUnicode– Default– OEM

The default is ASCII.

This parameter was introduced in Windows PowerShell 3.0.

-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.

-Path [<String[]>]

  • Default value is None
  • Accepts pipeline input ByValue

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

-UseCulture <SwitchParameter>

  • This value is required

Indicates that this cmdlet uses 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.

-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.

<CommonParameters>

This cmdlet supports the common parameters: Verbose, Debug,ErrorAction, ErrorVariable, WarningAction, WarningVariable,OutBuffer, PipelineVariable, and OutVariable.

Inputs

System.String

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

Outputs

Object

This cmdlet returns the objects described by the content in the CSV file.

Examples
  1. Import process objects:
    PS C:> Get-Process | Export-Csv processes.csv
    PS C:> $P = Import-Csv processes.csv
    PS C:> $P | Get-Member
    PS C:> $P | Format-Table
    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
       ...

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

    The first command uses the Get-Process cmdlet to get the processes 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.

    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.

    The third command uses a pipeline operator to pipe the imported objects to the Get-Member cmdlet. 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.

  2. Specify the delimiter:
    PS C:> Get-Process | Export-Csv processes.csv -Delimiter :
    PS C:> $P = Import-Csv processes.csv -Delimiter :
    

    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.

  3. Specify the current culture for the delimiter:
    PS C:> $P = Import-Csv processes.csv -UseCulture
    PS C:> (Get-Culture).textinfo.listseparator
    ,
    

    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.

  4. Change property names in an imported object:
    PS C:> Start-Job -ScriptBlock { Get-Process } | Export-Csv jobs.csv
    PS C:> $Header = "MoreData", "StatusMessage", "Location", "Command", "State", "Finished", "InstanceId", "SessionId", "Name", "ChildJobs", "Output", "Error", "Progress", "Verbose", "Debug", "Warning", "StateChanged"
    
       # 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
    PS C:> $J = Import-Csv jobs.csv -Header $Header
    PS C:> $J
    
       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  :

    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.

    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.

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

    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.

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

  5. Create a custom object using a 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.PS C:> $A = Import-Csv -Path .Links.csv -Header LinkID, TopicTitle
    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_AliasesPS 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

    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.

    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.

    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.

    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.

  6. Import a CSV that is missing a value:
    PS C:> Get-Content "\Server2c$TestProjects.csv"
    ProjectID, ProjectName,,Completed, Inventory, Redmond, True440, , FarEast, True, Marketing, Europe, FalsePS C:> Import-Csv "\Server2c$TestProjects.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           FalsePS C:>(Import-Csv "\Server2c$TestProjects.csv").H1
       RedmondFarEastEurope

    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.

    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.

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

Additional 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.
Related Links

ConvertFrom-Csv
ConvertTo-Csv
Export-Csv