CSV Files

We’ll be working with the .csv file type. CSV stands for “comma-separated values.” CSV files are tabular data structures (i.e. a spreadsheet), stored in a plain-text format. In .csv files, each line represents a row in the spreadsheet, and commas separate cells in each row (thus the file format name comma-separated values).

At first glance, .csv files look similar to proprietary spreadsheet program file formats, such as files saved in Microsoft Excel or Apple Numbers.

A few characteristics that distinguish .csv files (or other plain-text delimited data formats) from proprietary spreadsheet file types:

• Columns in a .csv file don’t have a value type. Everything is a string.

• Values in a .csv file don’t have font or color formatting

• .csv files only contain single worksheets

• .csv files don’t store formatting information like cell width/height

• .csv files don’t recognize merged cells or other kinds of special formatting (frozen or hidden rows/columns, embedded images, etc.)

Given these limitations, especially compared to the way we often interact with spreadsheet programs like Microsoft Excel or Google Sheets, what’s the advantage of working with .csv files?

One key advantage of .csv files is their simplicity. You can load or open a .csv file in a text editor and be able to quickly see the values in the file. When working with data in a programming environment, .csv files as a plain-text format simplify the process of loading structured data.

CSV & Python¶

Python’s csv module is a useful resource for working with this data structure (link to more detailed tutorial).