Skip to main content
IBM Quantum Platform
This page is from the dev version of Qiskit SDK. Go to the stable version.

Counts

class qiskit.result.Counts(data, time_taken=None, creg_sizes=None, memory_slots=None)

GitHub

Bases: dict

A class to store a counts result from a circuit execution.

Build a counts object

Parameters

  • data (dict) –

    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. All keys must be of the same format. This format must be one of the following.

    • A hexadecimal string of the form '0x4a'
    • A bit string prefixed with 0b, for example '0b1011'
    • A bit string with no prefix, for example '1011'
    • 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 don’t work and hex_outcomes() and int_outcomes() also do not work.
  • time_taken (float) – The duration of the experiment that generated the counts in seconds.

  • creg_sizes (list) – 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) – The number of total memory_slots in the experiment.

Raises

  • TypeError – If the input key type is not an int or str, or if the input keys are not all of the same type.
  • QiskitError – If a dit string key is input with creg_sizes and/or memory_slots.

Attributes

bitstring_regex

Default value: re.compile('^[01\\s]+$')


Methods

clear

clear()

Remove all items from the dict.

copy

copy()

Return a shallow copy of the dict.

fromkeys

classmethod fromkeys(iterable, value=None, /)

Create a new dictionary with keys from iterable and values set to value.

get

get(key, default=None, /)

Return the value for key if key is in the dictionary, else default.

hex_outcomes

hex_outcomes()

GitHub

Return a counts dictionary with hexadecimal string keys

Returns

A dictionary with the keys as hexadecimal strings instead of

bitstrings

Return type

dict

Raises

QiskitError – If the Counts object contains counts for dit strings

int_outcomes

int_outcomes()

GitHub

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

Raises

QiskitError – If the Counts object contains counts for dit strings

items

items()

Return a set-like object providing a view on the dict’s items.

keys

keys()

Return a set-like object providing a view on the dict’s keys.

most_frequent

most_frequent()

GitHub

Return the most frequent count

Returns

The bit string for the most frequent result

Return type

str

Raises

QiskitError – when there is >1 count with the same max counts, or an empty object.

pop

pop(k[, d]) → v, remove specified key and return the corresponding value.

If the key is not found, return the default if given; otherwise, raise a KeyError.

popitem

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.

setdefault

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.

shots

shots()

GitHub

Return the number of shots

update

update([E, ]**F) → None.  Update D from mapping/iterable E and F.

If E is present and has a .keys() method, then does: for k in E.keys(): 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]

values

values()

Return an object providing a view on the dict’s values.

Was this page helpful?
Report a bug, typo, or request content on GitHub.