Question

how does a file reader know where one data item begins and another starts in a data file? python recognizes the end of one data item and the beginning of the next because they are separated by a blank space an eol a bol a delimiter

Explanation:

In Python, data items in a file are separated by delimiters which can be commas, tabs, etc. A blank space is not always a reliable separator. EOL (End - of - Line) marks the end of a line and BOL (Begin - of - Line) marks the start of a line, but they are not general separators for data items. Delimiters are used to distinguish between different data elements.

Answer:

a delimiter