# cf.Datum.equals¶

Datum.equals(other, rtol=None, atol=None, verbose=None, ignore_data_type=False, ignore_fill_value=False, ignore_type=False)[source]

Whether two instances are the same.

Equality is strict by default. This means that:

• the named parameters must be the same, with the same values and data types, and vector-valued parameters must also have same the size and be element-wise equal (see the ignore_data_type parameter).

Two real numbers x and y are considered equal if |x-y|<=atol+rtol|y|, where atol (the tolerance on absolute differences) and rtol (the tolerance on relative differences) are positive, typically very small numbers. See the atol and rtol parameters.

Any type of object may be tested but, in general, equality is only possible with another object of the same type, or a subclass of one. See the ignore_type parameter.

Parameters
other:

The object to compare for equality.

atol: float, optional

The tolerance on absolute differences between real numbers. The default value is set by the cfdm.ATOL function.

rtol: float, optional

The tolerance on relative differences between real numbers. The default value is set by the cfdm.RTOL function.

verbose: int or None, optional

If an integer from 0 to 3, corresponding to increasing verbosity (else -1 as a special case of maximal and extreme verbosity), set for the duration of the method call (only) as the minimum severity level cut-off of displayed log messages, regardless of the global configured cfdm.LOG_LEVEL.

Else, if None (the default value), log messages will be filtered out, or otherwise, according to the value of the cfdm.LOG_LEVEL setting.

Overall, the higher a non-negative integer that is set (up to a maximum of 3) the more description that is printed to convey information about differences that lead to inequality.

ignore_data_type: bool, optional

If True then ignore the data types in all numerical comparisons. By default different numerical data types imply inequality, regardless of whether the elements are within the tolerance for equality.

ignore_type: bool, optional

Any type of object may be tested but, in general, equality is only possible with another object of the same type, or a subclass of one. If ignore_type is True then equality is possible for any object with a compatible API.

Returns
bool

Whether the two instances are equal.

Examples:

>>> d.equals(d)
True
>>> d.equals(d.copy())
True
>>> d.equals(None)
False