0-Based Numbering

0-based numbering is the computational idea of indexing an ordered data structure (e.g., a string or array) by starting with 0 instead of 1. For example, if $s$ is the string "ACGT", then $s[0]$ is given by the symbol 'A' and $s[1]$ is 'C'.

0-based numbering is used by default in a wide range of programming languages including Python.