Object Matchers

Matchers that inspect objects.

equal_to

hamcrest.core.core.isequal.equal_to(obj)

Matches if object is equal to a given object.

Parameters:obj – The object to compare against as the expected value.

This matcher compares the evaluated object to obj for equality.

has_length

hamcrest.library.object.haslength.has_length(match)

Matches if len(item) satisfies a given matcher.

Parameters:match – The matcher to satisfy, or an expected value for equal_to matching.

This matcher invokes the len function on the evaluated object to get its length, passing the result to a given matcher for evaluation.

If the match argument is not a matcher, it is implicitly wrapped in an equal_to matcher to check for :equality.

Examples:

has_length(greater_than(6))
has_length(5)

has_string

hamcrest.library.object.hasstring.has_string(match)

Matches if str(item) satisfies a given matcher.

Parameters:match – The matcher to satisfy, or an expected value for equal_to matching.

This matcher invokes the str function on the evaluated object to get its length, passing the result to a given matcher for evaluation. If the match argument is not a matcher, it is implicitly wrapped in an equal_to matcher to check for equality.

Examples:

has_string(starts_with('foo'))
has_string('bar')

has_property

hamcrest.library.object.hasproperty.has_property(name[, match])

Matches if object has a property with a given name whose value satisfies a given matcher.

Parameters:

• name – The name of the property.
• match – Optional matcher to satisfy.

This matcher determines if the evaluated object has a property with a given name. If no such property is found, has_property is not satisfied.

If the property is found, its value is passed to a given matcher for evaluation. If the match argument is not a matcher, it is implicitly wrapped in an equal_to matcher to check for equality.

If the match argument is not provided, the anything matcher is used so that has_property is satisfied if a matching property is found.

Examples:

has_property('name', starts_with('J'))
has_property('name', 'Jon')
has_property('name')

instance_of

hamcrest.core.core.isinstanceof.instance_of(atype)

Matches if object is an instance of, or inherits from, a given type.

Parameters:atype – The type to compare against as the expected type.

This matcher checks whether the evaluated object is an instance of atype or an instance of any class that inherits from atype.

Example:

instance_of(str)

none, not_none

hamcrest.core.core.isnone.none()

Matches if object is None.

hamcrest.core.core.isnone.not_none()

Matches if object is not None.

same_instance

hamcrest.core.core.issame.same_instance(obj)

Matches if evaluated object is the same instance as a given object.

Parameters:obj – The object to compare against as the expected value.

This matcher invokes the is identity operator to determine if the evaluated object is the the same object as obj.