qiskit-documentation/docs/api/qiskit/1.2/qiskit.result.Counts.mdx

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---
title: Counts (v1.2)
description: API reference for qiskit.result.Counts in qiskit v1.2
in_page_toc_min_heading_level: 1
python_api_type: class
python_api_name: qiskit.result.Counts
---
# Counts
<Class id="qiskit.result.Counts" isDedicatedPage={true} github="https://github.com/Qiskit/qiskit/tree/stable/1.2/qiskit/result/counts.py#L27-L189" signature="qiskit.result.Counts(data, time_taken=None, creg_sizes=None, memory_slots=None)" modifiers="class">
Bases: [`dict`](https://docs.python.org/3/library/stdtypes.html#dict "(in Python v3.13)")
A class to store a counts result from a circuit execution.
Build a counts object
**Parameters**
* **data** ([*dict*](https://docs.python.org/3/library/stdtypes.html#dict "(in Python v3.13)"))
The dictionary input for the counts. Where the keys represent a measured classical value and the value is an integer the number of shots with that result. The keys can be one of several formats:
> * A hexadecimal string of the form `'0x4a'`
> * A bit string prefixed with `0b` for example `'0b1011'`
> * A bit string formatted across register and memory slots. For example, `'00 10'`.
> * A dit string, for example `'02'`. Note for objects created with dit strings the `creg_sizes` and `memory_slots` kwargs dont work and [`hex_outcomes()`](#qiskit.result.Counts.hex_outcomes "qiskit.result.Counts.hex_outcomes") and [`int_outcomes()`](#qiskit.result.Counts.int_outcomes "qiskit.result.Counts.int_outcomes") also do not work.
* **time\_taken** ([*float*](https://docs.python.org/3/library/functions.html#float "(in Python v3.13)")) The duration of the experiment that generated the counts in seconds.
* **creg\_sizes** ([*list*](https://docs.python.org/3/library/stdtypes.html#list "(in Python v3.13)")) a nested list where the inner element is a list of tuples containing both the classical register name and classical register size. For example, `[('c_reg', 2), ('my_creg', 4)]`.
* **memory\_slots** ([*int*](https://docs.python.org/3/library/functions.html#int "(in Python v3.13)")) The number of total `memory_slots` in the experiment.
**Raises**
* [**TypeError**](https://docs.python.org/3/library/exceptions.html#TypeError "(in Python v3.13)") If the input key type is not an `int` or `str`.
* [**QiskitError**](exceptions#qiskit.exceptions.QiskitError "qiskit.exceptions.QiskitError") If a dit string key is input with `creg_sizes` and/or `memory_slots`.
## Attributes
### bitstring\_regex
<Attribute id="qiskit.result.Counts.bitstring_regex" attributeValue="re.compile('^[01\\s]+$')" />
## Methods
### clear
<Function id="qiskit.result.Counts.clear" signature="clear() → None.  Remove all items from D." />
### copy
<Function id="qiskit.result.Counts.copy" signature="copy() → a shallow copy of D" />
### fromkeys
<Function id="qiskit.result.Counts.fromkeys" signature="fromkeys(value=None, /)">
Create a new dictionary with keys from iterable and values set to value.
</Function>
### get
<Function id="qiskit.result.Counts.get" signature="get(key, default=None, /)">
Return the value for key if key is in the dictionary, else default.
</Function>
### hex\_outcomes
<Function id="qiskit.result.Counts.hex_outcomes" github="https://github.com/Qiskit/qiskit/tree/stable/1.2/qiskit/result/counts.py#L137-L158" signature="hex_outcomes()">
Return a counts dictionary with hexadecimal string keys
**Returns**
**A dictionary with the keys as hexadecimal strings instead of**
bitstrings
**Return type**
[dict](https://docs.python.org/3/library/stdtypes.html#dict "(in Python v3.13)")
**Raises**
[**QiskitError**](exceptions#qiskit.exceptions.QiskitError "qiskit.exceptions.QiskitError") If the Counts object contains counts for dit strings
</Function>
### int\_outcomes
<Function id="qiskit.result.Counts.int_outcomes" github="https://github.com/Qiskit/qiskit/tree/stable/1.2/qiskit/result/counts.py#L160-L180" signature="int_outcomes()">
Build a counts dictionary with integer keys instead of count strings
**Returns**
A dictionary with the keys as integers instead of bitstrings
**Return type**
[dict](https://docs.python.org/3/library/stdtypes.html#dict "(in Python v3.13)")
**Raises**
[**QiskitError**](exceptions#qiskit.exceptions.QiskitError "qiskit.exceptions.QiskitError") If the Counts object contains counts for dit strings
</Function>
### items
<Function id="qiskit.result.Counts.items" signature="items() → a set-like object providing a view on D's items" />
### keys
<Function id="qiskit.result.Counts.keys" signature="keys() → a set-like object providing a view on D's keys" />
### most\_frequent
<Function id="qiskit.result.Counts.most_frequent" github="https://github.com/Qiskit/qiskit/tree/stable/1.2/qiskit/result/counts.py#L118-L135" signature="most_frequent()">
Return the most frequent count
**Returns**
The bit string for the most frequent result
**Return type**
[str](https://docs.python.org/3/library/stdtypes.html#str "(in Python v3.13)")
**Raises**
[**QiskitError**](exceptions#qiskit.exceptions.QiskitError "qiskit.exceptions.QiskitError") when there is >1 count with the same max counts, or an empty object.
</Function>
### pop
<Function id="qiskit.result.Counts.pop" signature="pop(k[, d]) → v, remove specified key and return the corresponding value.">
If key is not found, default is returned if given, otherwise KeyError is raised
</Function>
### popitem
<Function id="qiskit.result.Counts.popitem" signature="popitem()">
Remove and return a (key, value) pair as a 2-tuple.
Pairs are returned in LIFO (last-in, first-out) order. Raises KeyError if the dict is empty.
</Function>
### setdefault
<Function id="qiskit.result.Counts.setdefault" signature="setdefault(key, default=None, /)">
Insert key with a value of default if key is not in the dictionary.
Return the value for key if key is in the dictionary, else default.
</Function>
### shots
<Function id="qiskit.result.Counts.shots" github="https://github.com/Qiskit/qiskit/tree/stable/1.2/qiskit/result/counts.py#L187-L189" signature="shots()">
Return the number of shots
</Function>
### update
<Function id="qiskit.result.Counts.update" signature="update([E, ]**F) → None.  Update D from dict/iterable E and F.">
If E is present and has a .keys() method, then does: for k in E: D\[k] = E\[k] If E is present and lacks a .keys() method, then does: for k, v in E: D\[k] = v In either case, this is followed by: for k in F: D\[k] = F\[k]
</Function>
### values
<Function id="qiskit.result.Counts.values" signature="values() → an object providing a view on D's values" />
</Class>