Make Method¶

Consider the following table definition from the article on table tiers:

@schema
class FilteredImage(dj.Computed):
    definition = """ # Filtered image
    -> Image
    ---
    filtered_image : longblob
    """

    def make(self, key):
        img = (test.Image & key).fetch1('image')
        key['filtered_image'] = my_filter(img)
        self.insert1(key)

The FilteredImage table can be populated as

FilteredImage.populate()

The make method receives one argument: the dict key containing the primary key value of an element of key source to be worked on.

Optional Arguments¶

The make method also accepts a number of optional arguments that provide more features and allow greater control over the method's behavior.

Argument	Default	Description
`restrictions`		A list of restrictions, restricting as `(tab.key_source & AndList (restrictions)) - tab.proj()`. Here `target` is the table to be populated, usually `tab` itself.
`suppress_errors`	`False`	If `True`, encountering an error will cancel the current `make` call, log the error, and continue to the next `make` call. Error messages will be logged in the job reservation table (if `reserve_jobs` is `True`) and returned as a list. See also `return_exception_objects` and `reserve_jobs`.
`return_exception_objects`	`False`	If `True`, error objects are returned instead of error messages. This applies only when `suppress_errors` is `True`.
`reserve_jobs`	`False`	If `True`, reserves job to indicate to other distributed processes. The job reservation table may be access as `schema.jobs`. Errors are logged in the jobs table.
`order`	`original`	The order of execution, either `"original"`, `"reverse"`, or `"random"`.
`limit`	`None`	If not `None`, checks at most this number of keys.
`max_calls`	`None`	If not `None`, populates at most this many keys. Defaults to no limit.
`display_progress`	`False`	If `True`, displays a progress bar.
`processes`	`1`	Number of processes to use. Set to `None` to use all cores
`make_kwargs`	`None`	Keyword arguments which do not affect the result of computation to be passed down to each `make()` call. Computation arguments should be specified within the pipeline e.g. using a `dj.Lookup` table.

Progress¶

The method table.progress reports how many key_source entries have been populated and how many remain. Two optional parameters allow more advanced use of the method. A parameter of restriction conditions can be provided, specifying which entities to consider. A Boolean parameter display (default is True) allows disabling the output, such that the numbers of remaining and total entities are returned but not printed.