csvclean - csvclean Documentation

Author

       Christopher Groskopf and contributors

Copyright

       2016, Christopher Groskopf and James McKinney

2.0.1                                             Jul 12, 2024                                       CSVCLEAN(1)

Description

Reports and fixes common errors in a CSV file.

Checks
• Reports rows that have a different number of columns than the header row, if the --length-mismatch
option is set.

• Reports columns that are empty, if the --empty-columns option is set.

TIP:
Enable all checks with --enable-all-checks (-a).

Fixes
• If a CSV has unquoted cells that contain line breaks, like:

id,address,country
1,1 Main St
Springfield,US
2,123 Acadia Avenue
London,GB

Use --join-short-rows to attempt to correct the errors by merging short rows into a single row:

id,address,country
1,"1 Main St
Springfield",US
2,"123 Acadia Avenue
London",GB

To change the string used to join the lines, use --separator. For example, with --separator",":

id,address,country
1,"1 Main St, Springfield",US
2,"123 Acadia Avenue, London",GB

• If a CSV has missing delimiters, like:

id,name,country
1,Alice
2,Bob,CA

You can add the missing delimiters with --fill-short-rows:

id,name,country
1,Alice,
2,Bob,CA

TIP:csvcut without options also adds missing delimiters!

To change the value used to fill short rows, use --fillvalue. For example, with --fillvalue"US":

id,name,country
1,Alice,US
2,Bob,CA

SEEALSO:--header-normalize-space under Usage.

NOTE:
Every csvkit tool does the following:

• Removes optional quote characters, unless the --quoting (-u) option is set to change this behavior

• Changes the field delimiter to a comma, if the input delimiter is set with the --delimiter (-d) or
--tabs (-t) options

• Changes the record delimiter to a line feed (LF or \n)

• Changes the quote character to a double-quotation mark, if the character is set with the --quotechar
(-q) option

• Changes the character encoding to UTF-8, if the input encoding is set with the --encoding (-e)
option

Outputcsvclean attempts to make the selected fixes. Then:

• If the --omit-error-rows option is set, only rows that pass the selected checks are written to standard
output. If not, all rows are written to standard output.

• If any checks are enabled, error rows along with line numbers and descriptions are written to standard
error. If there are error rows, the exit code is 1.

Usage
usage: csvclean [-h] [-d DELIMITER] [-t] [-q QUOTECHAR] [-u {0,1,2,3}] [-b]
[-p ESCAPECHAR] [-z FIELD_SIZE_LIMIT] [-e ENCODING] [-S] [-H]
[-K SKIP_LINES] [-v] [-l] [--zero] [-V]
[FILE]

Fix common errors in a CSV file.

positional arguments:
FILE The CSV file to operate on. If omitted, will accept
input as piped data via STDIN.

optional arguments:
-h, --help show this help message and exit
--length-mismatch Report data rows that are shorter or longer than the
header row.
--empty-columns Report empty columns as errors.
-a, --enable-all-checks
Enable all error reporting.
--omit-error-rows Omit data rows that contain errors, from standard
output.
--label LABEL Add a "label" column to standard error. Useful in
automated workflows.
--header-normalize-space
Strip leading and trailing whitespace and replace
sequences of whitespace characters by a single space
in the header.
--join-short-rows Merges short rows into a single row.
--separator SEPARATOR
The string with which to join short rows. Defaults to
a newline.
--fill-short-rows Fill short rows with the missing cells.
--fillvalue FILLVALUE
The value with which to fill short rows. Defaults to
none.

Examples

       Test a file with data rows that are shorter and longer than the header row:

          $ csvclean examples/bad.csv 2> errors.csv
          column_a,column_b,column_c
          0,mixed types.... uh oh,17
          $ cat errors.csv
          line_number,msg,column_a,column_b,column_c
          1,"Expected 3 columns, found 4 columns",1,27,,I'm too long!
          2,"Expected 3 columns, found 2 columns",,I'm too short!

       NOTE:
          If  any  data  rows  are longer than the header row, you need to add columns manually: for example, by
          adding one or more delimiters (,) to the end of the header row. csvclean can't do this, because it  is
          designed to work with standard input, and correcting an error at the start of the CSV data based on an
          observation  later  in the CSV data would require holding all the CSV data in memory – which is not an
          option for large files.

       Test a file with empty columns:

          $ csvclean --empty-columns examples/test_empty_columns.csv 2> errors.csv
          a,b,c,,
          a,,,,
          ,,c,,
          ,,,,
          $ cat errors.csv
          line_number,msg,a,b,c,,
          1,"Empty columns named 'b', '', ''! Try: csvcut -C 2,4,5",,,,,

       Use csvcut to exclude the empty columns:

          $ csvcut -C 2,4,5 examples/test_empty_columns.csv
          a,c
          a,
          ,c
          ,

       To change the line ending from line feed (LF or \n) to carriage return and line feed (CRLF or \r\n) use:

          csvformat -M $'\r\n' examples/dummy.csv

Name

       csvclean - csvclean Documentation