# Register
`qualtran.Register`


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<td>
  <a target="_blank" href="https://github.com/quantumlib/Qualtran/blob/main/qualtran/_infra/registers.py#L46-L127">
    <img src="https://www.tensorflow.org/images/GitHub-Mark-32px.png" />
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  </a>
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A register serves as the input/output quantum data specifications in a bloq's `Signature`.

<pre class="devsite-click-to-copy prettyprint lang-py tfo-signature-link">
<code>qualtran.Register(
    name,
    dtype,
    shape=attr_dict[&#x27;_shape&#x27;].default,
    side=attr_dict[&#x27;side&#x27;].default
)
</code></pre>



<!-- Placeholder for "Used in" -->

Each register has a name and a quantum data type. A collection of `Register` objects are used
to define a bloq's signature, see the `Signature` class.



<h2 class="add-link">Attributes</h2>

`name`<a id="name"></a>
: The string name of the register. This name is used to 'wire up' quantum inputs
  by name, analogous to Python's keyword-arguments.

`dtype`<a id="dtype"></a>
: The quantum data type of the register, for example `QBit()`, `QUInt(n)`, `QAny(n)`,
  or any of the data types provided in the top-level <a href="../qualtran.html"><code>qualtran</code></a> namespace.

`shape`<a id="shape"></a>
: An optional tuple of integer dimensions to declare a multidimensional register. The
  total number of bits is the product of entries in this tuple times `bitsize`.

`side`<a id="side"></a>
: Whether this is a left, right, or thru register. See the documentation for `Side`
  for more information.

`bitsize`<a id="bitsize"></a>
: &nbsp;

`shape_symbolic`<a id="shape_symbolic"></a>
: &nbsp;




## Methods

<h3 id="is_symbolic"><code>is_symbolic</code></h3>

<a target="_blank" class="external" href="https://github.com/quantumlib/Qualtran/blob/main/qualtran/_infra/registers.py#L75-L76">View source</a>

<pre class="devsite-click-to-copy prettyprint lang-py tfo-signature-link">
<code>is_symbolic() -> bool
</code></pre>




<h3 id="all_idxs"><code>all_idxs</code></h3>

<a target="_blank" class="external" href="https://github.com/quantumlib/Qualtran/blob/main/qualtran/_infra/registers.py#L92-L94">View source</a>

<pre class="devsite-click-to-copy prettyprint lang-py tfo-signature-link">
<code>all_idxs() -> Iterable[Tuple[int, ...]]
</code></pre>

Iterate over all possible indices of a multidimensional register.


<h3 id="total_bits"><code>total_bits</code></h3>

<a target="_blank" class="external" href="https://github.com/quantumlib/Qualtran/blob/main/qualtran/_infra/registers.py#L96-L101">View source</a>

<pre class="devsite-click-to-copy prettyprint lang-py tfo-signature-link">
<code>total_bits() -> int
</code></pre>

The total number of bits in this register.

This is the product of bitsize and each of the dimensions in `shape`.

<h3 id="total_qubits"><code>total_qubits</code></h3>

<a target="_blank" class="external" href="https://github.com/quantumlib/Qualtran/blob/main/qualtran/_infra/registers.py#L103-L109">View source</a>

<pre class="devsite-click-to-copy prettyprint lang-py tfo-signature-link">
<code>total_qubits() -> int
</code></pre>

The total number of qubits in this register.

This is the product of the register's data type's number of qubits
and each of the dimensions in `shape`.

<h3 id="total_cbits"><code>total_cbits</code></h3>

<a target="_blank" class="external" href="https://github.com/quantumlib/Qualtran/blob/main/qualtran/_infra/registers.py#L111-L117">View source</a>

<pre class="devsite-click-to-copy prettyprint lang-py tfo-signature-link">
<code>total_cbits() -> int
</code></pre>

The total number of classical bits in this register.

This is the product of the register's data type's number of classical bits
and each of the dimensions in `shape`.

<h3 id="adjoint"><code>adjoint</code></h3>

<a target="_blank" class="external" href="https://github.com/quantumlib/Qualtran/blob/main/qualtran/_infra/registers.py#L119-L127">View source</a>

<pre class="devsite-click-to-copy prettyprint lang-py tfo-signature-link">
<code>adjoint() -> 'Register'
</code></pre>

Return the 'adjoint' of this register by switching RIGHT and LEFT registers.


<h3 id="__ne__"><code>__ne__</code></h3>

<pre class="devsite-click-to-copy prettyprint lang-py tfo-signature-link">
<code>__ne__(
    other
)
</code></pre>

Check equality and either forward a NotImplemented or return the result negated.


<h3 id="__eq__"><code>__eq__</code></h3>

<pre class="devsite-click-to-copy prettyprint lang-py tfo-signature-link">
<code>__eq__(
    other
)
</code></pre>

Method generated by attrs for class Register.