$3\mathrm{.}7$ JOIN Operator $--$ You Provide It $($Submission $3)$

Actions

Implement the JOIN operator.

join $($relation$\_$one, relation$\_$two, condition$)$

Performs Theta JOIN on two relations

Parameters:

relation$\_$one: Table Object, the R$1$ relation in the theta join

relation$\_$two: Table Object, the R$2$ relation in the theta join

condition: str$,$ the condition for theta join

Returns:

Table Object, the resulted relation after R$1\backslash$theta R$2$

IMPORTANT Join uses caresian function. Cartesian adds $"\_$x$"$ and $"\_$y$"$ to relation attribute names. Specify the colum name accordingly in join condition.

Attributes mentioned in the join condition must exist in either relation. Otherwise, print error message "Condition Syntax Error" and return None.

DO NOT use pandas methods to construct operator function. You can use:

python's list$/$dictionary manipulation

the utility functions provided above

other relational operators implemented in this notebook

Columns in result$/$output can be displayed in any order.

We don't have any requirement on the Table name.

You don't need to remove the duplicates.