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Counts

class Counts(data, time_taken=None, creg_sizes=None, memory_slots=None)

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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. 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) – The duration of the experiment that generated the counts

  • 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 string
  • QiskitError – If a dit string key is input with creg_sizes and/or memory_slots

Methods

clear

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

copy

Counts.copy() → a shallow copy of D

fromkeys

Counts.fromkeys(value=None, /)

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

get

Counts.get(key, default=None, /)

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

hex_outcomes

Counts.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

Raises

QiskitError – If the Counts object contains counts for dit strings

int_outcomes

Counts.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

Raises

QiskitError – If the Counts object contains counts for dit strings

items

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

keys

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

most_frequent

Counts.most_frequent()

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

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

If key is not found, d is returned if given, otherwise KeyError is raised

popitem

Counts.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

Counts.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

Counts.shots()

Return the number of shots

update

Counts.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

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


Attributes

bitstring_regex

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

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