Array Generation

When array is adopted as type, ranjg.gen returns a list randomly.

>>> import ranjg
>>> schema = { 'type': 'array' }
>>> generated = ranjg.gen(schema)  # -> returns a list
>>> type(generated)
<class 'list'>

Length

When generating a list, you can limit the length of the list by specifying minItems or maxItems.

>>> import ranjg
>>> schema = {
...     'type': 'array',
...     'minItems': 2,
...     'maxItems': 4,
... }
>>> generated = ranjg.gen(schema)  # -> returns a list
>>> assert len(generated) >= 2
>>> assert len(generated) <= 4

Items

The keyword items can be a schema or an list of schemas, each of which specifies the elements of the generated array.

To All Elements

If items is a dict (it must be schema), each of element of the generated list satisfies the schema.

>>> import ranjg
>>> schema = {
...     'type': 'array',
...     'items': {
...         'type': 'string'
...     }
... }
>>> generated = ranjg.gen(schema)  # -> returns a list
>>> for element in generated:
...     assert isinstance(element, str)

To Each Element

On the other hand, if items is a list (its elements must be schema), each element of the generated list satisfies the corresponding schema in the list.

>>> import ranjg
>>> schema = {
...     'type': 'array',
...     'items': [
...         { 'type': 'string' },
...         { 'type': 'boolean' },
...         { 'type': 'array' },
...     ]
... }
>>> generated = ranjg.gen(schema)  # -> returns a list
>>> if len(generated) >= 1:
...     assert isinstance(generated[0], str)
>>> if len(generated) >= 2:
...     assert isinstance(generated[1], bool)
>>> if len(generated) >= 3:
...     assert isinstance(generated[2], list)

note: Even if items is a list of length 3, the length of the generated list is not necessarily 3, but may be longer or shorter than that. (However, if additionalItems is set to False as described below, the number of elements in the generated list will not exceed the number of elements in items.) The length of the generated list can be specified with the keywords minItems and maxItems.

If items is a list, it isn’t limit overflowing elements. For example, if the length of items is 3, nothing is specified for the 4th and subsequent elements of the generated list.

>>> import ranjg
>>> schema = {
...     'type': 'array',
...     'items': [
...         { 'type': 'string' },
...         { 'type': 'boolean' },
...         { 'type': 'array' },
...     ]
... }
>>> generated = ranjg.gen(schema)  # -> returns a list
>>> # generated[3] was freely generated (if it exists).

You can avoid this by specifying a schema for additionalItems. If additionalItems is a schema, the schema will be specified for elements that exceed the number of items elements.

>>> import ranjg
>>> schema = {
...     'type': 'array',
...     'items': [
...         { 'type': 'string' },
...         { 'type': 'boolean' },
...         { 'type': 'array' },
...     ],
...     'additionalItems': { 'type': 'integer' },
... }
>>> generated = ranjg.gen(schema)  # -> returns a list
>>> if len(generated) >= 1:
...     assert isinstance(generated[0], str)
>>> if len(generated) >= 2:
...     assert isinstance(generated[1], bool)
>>> if len(generated) >= 3:
...     assert isinstance(generated[2], list)
>>> for i in range(3, len(generated)):
...     assert isinstance(generated[i], int)

If you don’t want to allow additional elements that are not specified in items, set False to additionalItems.

>>> import ranjg
>>> schema = {
...     'type': 'array',
...     'items': [
...         { 'type': 'string' },
...         { 'type': 'boolean' },
...         { 'type': 'array' },
...     ],
...     'additionalItems': False,
... }
>>> generated = ranjg.gen(schema)  # -> returns a list
>>> assert len(generated) <= len(schema['items'])

note: If additionalItems is True or not specified, options.default_schema_of_items is used to generate elements whose schema is not specified in items. See also Options for Array Generation.

Not Specified

If items is not specified, options.default_schema_of_items is used instead. See also Options for Array Generation.