`parasite.string`¶

Brief¶

Reference for the string submodule of the parasite package. This submodule contains the parasite.string.String class, which is a generic container for a string Python object.

Usage¶

from parasite import p

schema = p.string().min(3).max(10)

schema.parse("hello")  # -> "hello"
...

Member Reference¶

class parasite.string.K¶

Template type for the key in a dictionary.

alias of TypeVar(‘K’)

class parasite.string.String[source]¶

parasite type for creating and parsing string based schemas. Will return a python str with the parsed values on success.

Inheritance:

optional() → String[source]¶

Makes the value optional, when parsing with _find_and_parse(). Has no effect on parse(). Inverse of required().

Warning

This function has no effect if the value is parsed as a standalone value.

Returns:: The updated instance of the class.
Return type:: String

Example usage:

Lets assume we have the following schemas:

from parasite import p

schema = p.obj({ "name": p.string().optional() })
schema2 = p.obj({ "name": p.string() })

The resulting schemas will parse the following objects:

>>> schema.parse({ "name": "John" })
{ "name": "John" }
>>> schema.parse({ })
{ }

>>> schema2.parse({ "name": "John" })
{ "name": "John" }
>>> schema2.parse({ })
ValidationError: key "name" not found, but is required

required() → String[source]¶

Makes the value required, when parsing with _find_and_parse(). Has no effect on parse(). Inverse of optional(). Default behavior.

Note

This function is default behavior for the class and therefore only has an effect if the function optional() may have been called before.

Warning

This function has no effect if the value is parsed as a standalone value.

Returns:: The updated instance of the class.
Return type:: String

Example usage:

Lets assume we have the following schemas:

from parasite import p

schema = p.obj({ "name": p.string().optional().required() })
schema2 = p.obj({ "name": p.string() })

The resulting schemas will parse the following objects:

>>> schema.parse({ "name": "John" })
{ "name": "John" }
>>> schema.parse({ })
ValidationError: key "name" not found, but is required

>>> schema2.parse({ "name": "John" })
{ "name": "John" }
>>> schema2.parse({ })
ValidationError: key "name" not found, but is required

nullable() → String[source]¶

Makes the value nullable, when parsing with _find_and_parse(). Has no effect on parse(). Inverse of not_nullable().

Warning

This function has no effect if the value is parsed as a standalone value.

Returns:: The updated instance of the class.
Return type:: String

Example usage:

Lets assume we have the following schemas:

from parasite import p

schema = p.obj({ "name": p.string().nullable() })
schema2 = p.obj({ "name": p.string() })

The resulting schemas will parse the following objects:

>>> schema.parse({ "name": "John" })
{ "name": "John" }
>>> schema.parse({ "name": None })
{ "name": None }

>>> schema2.parse({ "name": "John" })
{ "name": "John" }
>>> schema2.parse({ "name": None })
ValidationError: key "name" is not nullable, but is None

not_nullable() → String[source]¶

Makes the value not-nullable, when parsing with _find_and_parse(). Has no effect on parse(). Default behavior. Inverse of nullable().

Note

This function is default behavior for the class and therefore only has an effect if the function nullable() may have been called before.

Warning

This function has no effect if the value is parsed as a standalone value.

Returns:: The updated instance of the class.
Return type:: String

Example usage:

Lets assume we have the following schemas:

from parasite import p

schema = p.obj({ "name": p.string().nullable().not_nullable() })
schema2 = p.obj({ "name": p.string() })

The resulting schemas will parse the following objects:

>>> schema.parse({ "name": "John" })
{ "name": "John" }
>>> schema.parse({ "name": None })
ValidationError: key "name" is not nullable, but is None

>>> schema2.parse({ "name": "John" })
{ "name": "John" }
>>> schema2.parse({ "name": None })
ValidationError: key "name" is not nullable, but is None