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Learn CSV / CSV Overview

Comma-separated-value (CSV) files are perhaps the simplest format that can be used for a dataset. It is for this reason that CSV files are generally supported by many tools, including spreadsheets, database import/export, open data portals, geographic information systems, visualization tools, and other software tools. The basic syntax of a CSV file is columns of data separated by a comma. An alternate delimiter character can be used. For example, using a tab character as delimiter would result in tab-delimited-file. The pipe or vertical bar (|) is another common delimiter. An example CSV file, with heading and data rows is as follows:

"column1","column2","column3"
text one,123,123.0
text two,234,234.0
text three,345,345.0

CSV files may be used as the master copy of a dataset or a data exchange format created from a master copy. In both cases, dealing with the limitations of CSV is critical to ensuring data integrity.

The CSV Syntax documentation describes syntax and limitations.

CSV Benefits

  • Very simple format that can be handled by many software programs
  • File size is generally small because the file mainly consists of data values and often compresses well

CSV Limitations

  • No native metadata format and therefore requires assumptions or implementation-specific approach
  • Can be difficult to view/edit in a text editor due to lack of formatting
  • Errors in formatting (such as commas used in data) can be difficult to detect due to simple format