Edit page in Livemark
(2022-09-19 18:33)

Package Class

The Data Package is a core Frictionless Data concept meaning a set of resources with additional metadata provided. You can read Data Package Standard for more information.

Creating Package

Let's create a data package:

Python

from frictionless import Package, Resource

package = Package('table.csv') # from a resource path
package = Package('tables/*') # from a resources glob
package = Package(['tables/chunk1.csv', 'tables/chunk2.csv']) # from a list
package = Package('package/datapackage.json') # from a descriptor path
package = Package({'resources': {'path': 'table.csv'}}) # from a descriptor
package = Package(resources=[Resource(path='table.csv')]) # from arguments

As you can see it's possible to create a package providing different kinds of sources which will be detected to have some type automatically (e.g. whether it's a glob or a path). It's possible to make this step more explicit:

Python

from frictionless import Package, Resource

package = Package(resources=[Resource(path='table.csv')]) # from arguments
package = Package('datapackage.json') # from a descriptor

Describing Package

The standards support a great deal of package metadata which is possible to have with Frictionless Framework too:

Python

from frictionless import Package, Resource

package = Package(
    name='package',
    title='My Package',
    description='My Package for the Guide',
    resources=[Resource(path='table.csv')],
    # it's possible to provide all the official properties like homepage, version, etc
)
print(package)

{'name': 'package',
 'title': 'My Package',
 'description': 'My Package for the Guide',
 'resources': [{'path': 'table.csv'}]}

If you have created a package, for example, from a descriptor you can access this properties:

Python

from frictionless import Package

package = Package('datapackage.json')
print(package.name)
# and others

test-tabulator

And edit them:

Python

from frictionless import Package

package = Package('datapackage.json')
package.name = 'new-name'
package.title = 'New Title'
package.description = 'New Description'
# and others
print(package)

{'name': 'new-name',
 'title': 'New Title',
 'description': 'New Description',
 'resources': [{'name': 'first-resource',
                'path': 'table.xls',
                'schema': {'fields': [{'name': 'id', 'type': 'number'},
                                      {'name': 'name', 'type': 'string'}]}},
               {'name': 'number-two',
                'path': 'table-reverse.csv',
                'schema': {'fields': [{'name': 'id', 'type': 'integer'},
                                      {'name': 'name', 'type': 'string'}]}}]}

Resource Management

The core purpose of having a package is to provide an ability to have a set of resources. The Package class provides useful methods to manage resources:

Python

from frictionless import Package, Resource

package = Package('datapackage.json')
print(package.resources)
print(package.resource_names)
package.add_resource(Resource(name='new', data=[['key1', 'key2'], ['val1', 'val2']]))
resource = package.get_resource('new')
print(package.has_resource('new'))
package.remove_resource('new')

[{'name': 'first-resource',
 'path': 'table.xls',
 'schema': {'fields': [{'name': 'id', 'type': 'number'},
                       {'name': 'name', 'type': 'string'}]}}, {'name': 'number-two',
 'path': 'table-reverse.csv',
 'schema': {'fields': [{'name': 'id', 'type': 'integer'},
                       {'name': 'name', 'type': 'string'}]}}]
['first-resource', 'number-two']
True

Saving Descriptor

As any of the Metadata classes the Package class can be saved as JSON or YAML:

Python

from frictionless import Package
package = Package('tables/*')
package.to_json('datapackage.json') # Save as JSON
package.to_yaml('datapackage.yaml') # Save as YAML

Package (class)

Manager (class)

Package (class)

Package representation This class is one of the cornerstones of of Frictionless framework. It manages underlaying resource and provides an ability to describe a package. ```python package = Package(resources=[Resource(path="data/table.csv")]) package.get_resoure('table').read_rows() == [ {'id': 1, 'name': 'english'}, {'id': 2, 'name': '中国人'},

Signature

(source: Optional[Any] = None, control: Optional[Control] = None, innerpath: Optional[str] = None, *, name: Optional[str] = None, title: Optional[str] = None, description: Optional[str] = None, homepage: Optional[str] = None, profiles: List[Union[IProfile, str]] = [], licenses: List[dict] = [], sources: List[dict] = [], contributors: List[dict] = [], keywords: List[str] = [], image: Optional[str] = None, version: Optional[str] = None, created: Optional[str] = None, resources: List[Union[Resource, str]] = [], basepath: Optional[str] = None, detector: Optional[Detector] = None, dialect: Optional[Dialect] = None, catalog: Optional[Catalog] = None)