Data type routines

can_cast(from_, to[, casting])

Returns True if cast between data types can occur according to the casting rule.

promote_types(type1, type2)

Returns the data type with the smallest size and smallest scalar kind to which both type1 and type2 may be safely cast.


For scalar a, returns the data type with the smallest size and smallest scalar kind which can hold its value.


Returns the type that results from applying the NumPy type promotion rules to the arguments.


Return a scalar type which is common to the input arrays.

obj2sctype(rep[, default])

Return the scalar dtype or NumPy equivalent of Python type of an object.

Creating data types



format_parser(formats, names, titles[, …])

Class to convert formats, names, titles description to a dtype.

Data type information


Machine limits for floating point types.


Machine limits for integer types.

MachAr([float_conv, int_conv, …])

Diagnosing machine parameters.

Data type testing


Determines whether the given object represents a scalar data-type.

issubdtype(arg1, arg2)

Returns True if first argument is a typecode lower/equal in type hierarchy.

issubsctype(arg1, arg2)

Determine if the first argument is a subclass of the second argument.

issubclass_(arg1, arg2)

Determine if a class is a subclass of a second class.

find_common_type(array_types, scalar_types)

Determine common type following standard coercion rules.



Return a description for the given data type code.


Return the string representation of a scalar dtype.

mintypecode(typechars[, typeset, default])

Return the character for the minimum-size type to which given types can be safely cast.


Return the scalar type of highest precision of the same kind as the input.