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Counts

qiskit.result.Counts(data, time_taken=None, creg_sizes=None, memory_slots=None)GitHub(opens in a new tab)

Bases: dict(opens in a new tab)

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

Build a counts object

Parameters

  • data (dict(opens in a new tab)) –

    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 don’t work and hex_outcomes() and int_outcomes() also do not work.
  • time_taken (float(opens in a new tab)) – The duration of the experiment that generated the counts in seconds.

  • creg_sizes (list(opens in a new tab)) – 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(opens in a new tab)) – The number of total memory_slots in the experiment.

Raises


Attributes

bitstring_regex

= re.compile('^[01\\s]+$')


Methods

clear

clear() → None.  Remove all items from D.

copy

copy() → a shallow copy of D

fromkeys

fromkeys(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()

Return a counts dictionary with hexadecimal string keys

Returns

A dictionary with the keys as hexadecimal strings instead of

bitstrings

Return type

dict(opens in a new tab)

Raises

QiskitError – If the Counts object contains counts for dit strings

int_outcomes

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(opens in a new tab)

Raises

QiskitError – If the Counts object contains counts for dit strings

items

items() → a set-like object providing a view on D's items

keys

keys() → a set-like object providing a view on D's keys

most_frequent

most_frequent()

Return the most frequent count

Returns

The bit string for the most frequent result

Return type

str(opens in a new tab)

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 key is not found, default is returned if given, otherwise KeyError is raised

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()

Return the number of shots

update

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]

values

values() → an object providing a view on D's values

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