Add way to query a Table

Sometimes is really handy to just have a rows.Table filtered (like we would do using Django ORM with the .objects.filter method).

I don't know if the best option for rows API is to add a filter/query method into rows.Table (will return a new rows.Table object) or just create a helper function. In my scripts I'm currently creating helper functions so I can feel better how the API should be.

The implementation would be something like this:

def filter_row(row, kwargs):
    for key, value in kwargs.items():
        if getattr(row, key) != value:
            break
    else:
        return True
    return False


def query_table(table, *args, **kwargs):
    new_table = rows.Table(fields=table.fields)
    # TODO: should also add _meta and other Table attributes
    new_table.extend(row._asdict() for row in table if filter_row(row, kwargs))
    return new_table

Start by locating the rows.Table implementation and reviewing how Table fields and other attributes are represented. Compare the proposed filter_row and query_table helpers with the existing API, then define the filtering API and metadata-preservation behavior before adding coverage for the chosen behavior.