[gdal-dev] Ogr2ogr CSV driver not handling correctly line breaks inside columns

Robert Hewlett rob.hewy at gmail.com
Wed May 3 09:38:08 PDT 2023 

Hi,

Not to start a controversy but it feels like the standard hints at three
files. Did the standard change?

If it is three files which works for me in QGIS and geopandas i.e. data
lands where it is suppose to, then more layer creations options are needed
to handle the SRID/CRS

CREATE_PRJ=YES/NO
or -t_srs and/or -s_srs triggers the dot-prj file being created.

Just saying 😊.

In the meantime would a short python script help parse the one file into
three?


On Wed, May 3, 2023 at 9:16 AM Moises Calzado via gdal-dev <
gdal-dev at lists.osgeo.org> wrote:

> Hi Robert,
>
> Yes, we're getting one with all the info!
>
> El mié, 3 may 2023 a las 18:14, Robert Hewlett (<rob.hewy at gmail.com>)
> escribió:
>
>> Just to clarify, instead of getting three files you are getting one with
>> all the info: types, projection, data?
>>
>> https://giswiki.hsr.ch/GeoCSV
>>
>> On Wed, May 3, 2023 at 8:57 AM Moises Calzado via gdal-dev <
>> gdal-dev at lists.osgeo.org> wrote:
>>
>>> We're also specifying the GEOM_POSSIBLE_NAMES, so it would be great if
>>> with that option we could use the GEOMETRY_NAME without using the
>>> CREATE_CSVT=YES option.
>>>
>>> Regarding emitting the .prj and .csvt in /vsistdout mode, that's why I'm
>>> saying that there is an issue while generating the resultant CSV.
>>> The way we see it is that when using the /vsistdout mode, the result is
>>> a CSV file with the .prj information in the first line, and the .csvt in
>>> the second line. We're dealing with the result deleting the first two lines
>>> and using the rest of the content as a CSV, which should be equal to the
>>> result obtained when using ogr2ogr without the CREATE_CSVT=YES option.
>>> Probably we're losing something, but as we see it, the generated CSV
>>> should be a valid one. Does that make sense?
>>>
>>> Thanks so much for your help!
>>>
>>> El mié, 3 may 2023 a las 15:10, Robert Hewlett (<rob.hewy at gmail.com>)
>>> escribió:
>>>
>>>> The .CSVT and .PRJ help to make a proper geocsv dataset. Helps with
>>>> QGIS And geopandas. The column name that I use in the CSV is usually geom
>>>> and WKT shows up in the CSVT file which seems to be a one line file that
>>>> hints at the data types in the CSV file.
>>>>
>>>> I hope that makes sense.
>>>>
>>>> CSVT
>>>> Integer, Integer,WKT
>>>>
>>>> CSV
>>>> line_id,point_id,geom
>>>> 1,1,"POINT(1000 1000)"
>>>>
>>>> PRJ
>>>> EPSG:26910
>>>>
>>>>
>>>>
>>>>
>>>> On Wed, May 3, 2023, 05:23 Moises Calzado via gdal-dev <
>>>> gdal-dev at lists.osgeo.org> wrote:
>>>>
>>>>> Hi Even,
>>>>>
>>>>> Thanks so much for taking a look into that one!
>>>>>
>>>>> I have one doubt regarding the CSVT content, as we're not really using
>>>>> it, but it's required when using the GEOMETRY_NAME layer creation option,
>>>>> as can be checked in the CSV driver documentation:
>>>>>
>>>>>
>>>>>>    -
>>>>>>
>>>>>>    GEOMETRY_NAME=name (Starting with GDAL 2.1): Name of geometry
>>>>>>    column. Only used if GEOMETRY=AS_WKT and CREATE_CSVT=YES. Defaults to WKT
>>>>>>
>>>>>> We really need this flag as we are processing files that contain
>>>>> geometries with different column names, and we always want the same
>>>>> geometry name in the generated output. Are we losing something when using
>>>>> that flag to avoid this problem?
>>>>> In my humble opinion, generating an invalid CSV when using the -lco
>>>>> CREATE_CSVT=YES looks like a bug for me, as I can't see the reason why
>>>>> strings containing line breaks can't be quoted.
>>>>>
>>>>> Could you please shed some light on this?
>>>>>
>>>>> Looking forward to your reply,
>>>>> Regards.
>>>>>
>>>>> El mié, 3 may 2023 a las 14:00, Even Rouault (<
>>>>> even.rouault at spatialys.com>) escribió:
>>>>>
>>>>>> you didn't post to the list
>>>>>> Le 03/05/2023 à 13:49, Moises Calzado a écrit :
>>>>>>
>>>>>> Hi Even,
>>>>>>
>>>>>> Thanks so much for taking a look into that one!
>>>>>>
>>>>>> I have one doubt regarding the CSVT content, as we're not really
>>>>>> using it, but it's required when using the GEOMETRY_NAME layer creation
>>>>>> option, as can be checked in the CSV driver documentation:
>>>>>>
>>>>>>
>>>>>>>    -
>>>>>>>
>>>>>>>    GEOMETRY_NAME=name (Starting with GDAL 2.1): Name of geometry
>>>>>>>    column. Only used if GEOMETRY=AS_WKT and CREATE_CSVT=YES. Defaults to WKT
>>>>>>>
>>>>>>> We really need this flag as we are processing files that contain
>>>>>> geometries with different column names, and we always want the same
>>>>>> geometry name in the generated output. Are we losing something when using
>>>>>> that flag to avoid this problem?
>>>>>> In my humble opinion, generating an invalid CSV when using the -lco
>>>>>> CREATE_CSVT=YES looks like a bug for me, as I can't see the reason why
>>>>>> strings containing line breaks can't be quoted.
>>>>>>
>>>>>> Could you please shed some light on this?
>>>>>>
>>>>>> Looking forward to your reply,
>>>>>> Regards.
>>>>>>
>>>>>> El sáb, 29 abr 2023 a las 15:44, Even Rouault (<
>>>>>> even.rouault at spatialys.com>) escribió:
>>>>>>
>>>>>>> Moises,
>>>>>>>
>>>>>>> as far as I can see with your example, the CSV driver behaves
>>>>>>> "properly" in reading and writing of field values with line breaks.
>>>>>>>
>>>>>>> It follows the "Fields with embedded line breaks must be quoted"
>>>>>>> rule of https://en.wikipedia.org/wiki/Comma-separated_values
>>>>>>>
>>>>>>> $ ogr2ogr out.csv /vsizip/dataframe.zip
>>>>>>>
>>>>>>> $ cat out.csv
>>>>>>> id,descriptio
>>>>>>> "1",This is my third row
>>>>>>> "2","this is
>>>>>>> my string
>>>>>>> "
>>>>>>> "3",This is my third row
>>>>>>>
>>>>>>> $ ogrinfo out.csv -al
>>>>>>> INFO: Open of `out.csv'
>>>>>>>       using driver `CSV' successful.
>>>>>>>
>>>>>>> Layer name: out
>>>>>>> Geometry: None
>>>>>>> Feature Count: 3
>>>>>>> Layer SRS WKT:
>>>>>>> (unknown)
>>>>>>> id: String (0.0)
>>>>>>> descriptio: String (0.0)
>>>>>>> OGRFeature(out):1
>>>>>>>   id (String) = 1
>>>>>>>   descriptio (String) = This is my third row
>>>>>>>
>>>>>>> OGRFeature(out):2
>>>>>>>   id (String) = 2
>>>>>>>   descriptio (String) = this is
>>>>>>> my string
>>>>>>>
>>>>>>>
>>>>>>> OGRFeature(out):3
>>>>>>>   id (String) = 3
>>>>>>>   descriptio (String) = This is my third row
>>>>>>>
>>>>>>> But in your example using /vsistdout/ and -lco CREATE_CSVT=YES is
>>>>>>> going to result in an invalid CSV file which will mix both the .csvt and
>>>>>>> .csv content
>>>>>>>
>>>>>>> Even
>>>>>>> Le 24/04/2023 à 13:34, Moises Calzado via gdal-dev a écrit :
>>>>>>>
>>>>>>> Hello!
>>>>>>>
>>>>>>> We're trying to convert a Shapefile into a CSV using ogr2ogr and
>>>>>>> we're having some issues while dealing with some columns that contain line
>>>>>>> breaks inside their values. If we have a line with the following string,
>>>>>>> ogr2ogr detects that the line break is a new line and it returns two lines.
>>>>>>>
>>>>>>> "this is my \n value"
>>>>>>>
>>>>>>>
>>>>>>> That's the command that we're executing:
>>>>>>>
>>>>>>> ogr2ogr -f CSV -skipfailures -makevalid /vsistdout/
>>>>>>>> /vsizip/shapefile.zip -simplify 0.00001 -dim XY -t_srs EPSG:4326 -lco
>>>>>>>> GEOMETRY=AS_WKT -lco GEOMETRY_NAME=geom -lco CREATE_CSVT=YES > result.csv
>>>>>>>>
>>>>>>>
>>>>>>> Is this an expected behaviour, or is there any way to avoid this?
>>>>>>> Sharing an example Shapefile so that you can try to reproduce that
>>>>>>> behaviour:
>>>>>>> https://drive.google.com/file/d/1gFqfTP02KTFoavJyyO-Ix05YwZB2tS24/view?usp=sharing
>>>>>>>
>>>>>>> Thanks so much in advance,
>>>>>>> Regards.
>>>>>>>
>>>>>>> --
>>>>>>> *Moises Calzado*
>>>>>>>
>>>>>>> Support Engineer
>>>>>>>
>>>>>>> +34671264286 | mcalzado at carto.com | CARTO <https://www.carto.com/>
>>>>>>> <https://spatial-data-science-conference.com/2023/london/>
>>>>>>>
>>>>>>> _______________________________________________
>>>>>>> gdal-dev mailing listgdal-dev at lists.osgeo.orghttps://lists.osgeo.org/mailman/listinfo/gdal-dev
>>>>>>>
>>>>>>> -- http://www.spatialys.com
>>>>>>> My software is free, but my time generally not.
>>>>>>>
>>>>>>>
>>>>>>
>>>>>> --
>>>>>> *Moises Calzado*
>>>>>>
>>>>>> Support Engineer
>>>>>>
>>>>>> +34671264286 | mcalzado at carto.com | CARTO <https://www.carto.com/>
>>>>>> <https://spatial-data-science-conference.com/2023/london/>
>>>>>>
>>>>>> -- http://www.spatialys.com
>>>>>> My software is free, but my time generally not.
>>>>>>
>>>>>>
>>>>>
>>>>> --
>>>>> *Moises Calzado*
>>>>>
>>>>> Support Engineer
>>>>>
>>>>> +34671264286 | mcalzado at carto.com | CARTO <https://www.carto.com/>
>>>>> <https://spatial-data-science-conference.com/2023/london/>
>>>>> _______________________________________________
>>>>> gdal-dev mailing list
>>>>> gdal-dev at lists.osgeo.org
>>>>> https://lists.osgeo.org/mailman/listinfo/gdal-dev
>>>>>
>>>> _______________________________________________
>>>> gdal-dev mailing list
>>>> gdal-dev at lists.osgeo.org
>>>> https://lists.osgeo.org/mailman/listinfo/gdal-dev
>>>>
>>>
>>>
>>> --
>>> *Moises Calzado*
>>>
>>> Support Engineer
>>>
>>> +34671264286 | mcalzado at carto.com | CARTO <https://www.carto.com/>
>>> <https://spatial-data-science-conference.com/2023/london/>
>>> _______________________________________________
>>> gdal-dev mailing list
>>> gdal-dev at lists.osgeo.org
>>> https://lists.osgeo.org/mailman/listinfo/gdal-dev
>>>
>> _______________________________________________
>> gdal-dev mailing list
>> gdal-dev at lists.osgeo.org
>> https://lists.osgeo.org/mailman/listinfo/gdal-dev
>>
>
>
> --
> *Moises Calzado*
>
> Support Engineer
>
> +34671264286 | mcalzado at carto.com | CARTO <https://www.carto.com/>
> <https://spatial-data-science-conference.com/2023/london/>
> _______________________________________________
> gdal-dev mailing list
> gdal-dev at lists.osgeo.org
> https://lists.osgeo.org/mailman/listinfo/gdal-dev
>
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