def read$\_$csv$($filename$)$:

$"""$

Returns the contents read from the CSV file filename.

This function reads the contents of the file filename and returns the contents as

a $2-$dimensional list. Each element of the list is a row, with the first row being

the header. Cells in each row are all interpreted as strings; it is up to the

programmer to interpret this data, since CSV files contain no type information.

Parameter filename: The file to read

Precondition: filename is a string, referring to a file that exists, and that file

is a valid CSV file

$"""$