[csv/en] New language CSV

csv.html.markdown

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+---
+category: Algorithms & Data Structures
+contributors:
+- [Timon Erhart, 'https://github.com/turbotimon/']
+---
+
+CSV (Comma-Separated Values) is a lightweight file format used to store tabular
+data in plain text, designed for easy data exchange between programs,
+particularly spreadsheets and databases. Its simplicity and human readability
+have made it a cornerstone of data interoperability. It is often used for
+moving data between programs with incompatible or proprietary formats.
+
+While RFC 4180 provides a standard for the format, in practice, the term "CSV"
+ is often used more broadly to refer to any text file that:
+
+- Can be interpreted as tabular data
+- Uses a delimiter to separate fields (columns)
+- Uses line breaks to separate records (rows)
+- Optionally includes a header in the first row
+
+```csv
+Name, Age, DateOfBirth
+Alice, 30, 1993-05-14
+Bob, 25, 1998-11-02
+Charlie, 35, 1988-03-21
+```
+
+## Delimiters for Rows and Columns
+
+Rows are typically separated by line breaks (`\n` or `\r\n`), while columns
+ (fields) are separated by a specific delimiter. Although commas are the most
+ common delimiter for fields, other characters, such as semicolons (`;`), are
+ commonly used in regions where commas are decimal separators (e.g., Germany).
+ Tabs (`\t`) are also used as delimiters in some cases, with such files often
+ referred to as "TSV" (Tab-Separated Values).
+
+Example using semicolons as delimiter and comma for decimal separator:
+
+```csv
+Name; Age; Grade
+Alice; 30; 50,50
+Bob; 25; 45,75
+Charlie; 35; 60,00
+```
+
+## Data Types
+
+CSV files do not inherently define data types. Numbers and dates are stored as
+ plain text, and their interpretation depends on the software importing the
+ file. Typically, data is interpreted as follows:
+
+```csv
+Data, Comment
+100, Interpreted as a number (integer)
+100.00, Interpreted as a number (floating-point)
+2024-12-03, Interpreted as a date or a string (depending on the parser)
+Hello World, Interpreted as text (string)
+"1234", Interpreted as text instead of a number
+```
+
+## Quoting Strings and Special Characters
+
+Quoting strings is only required if the string contains the delimiter, special
+ characters, or otherwise could be interpreted as a number. However, it is
+ often considered good practice to quote all strings to enhance readability and
+ robustness.
+
+```csv
+Quoting strings examples,
+Unquoted string,
+"Optionally quoted string (good practice)",
+"If it contains the delimiter, it needs to be quoted",
+"Also, if it contains special characters like \n newlines or \t tabs",
+"The quoting "" character itself typically is escaped by doubling the quote ("")",
+"or in some systems with a backslash \" (like other escapes)",
+```
+
+However, make sure that for one document, the quoting method is consistent.
+ For example, the last two examples of quoting with either "" or \" would
+ not be consistent and could cause problems.
+
+## Encoding
+
+Different encodings are used. Most modern CSV files use UTF-8 encoding, but
+ older systems might use others like ASCII or ISO-8859.
+
+If the file is transferred or shared between different systems, it is a good
+ practice to explicitly define the encoding used, to avoid issues with
+ character misinterpretation.
+
+## More Resources
+
++ [Wikipedia](https://en.wikipedia.org/wiki/Comma-separated_values)
++ [RFC 4180](https://datatracker.ietf.org/doc/html/rfc4180)