pygsti.baseobjs.label.LabelStr

pygsti.baseobjs.label.LabelStr#

class LabelStr(name, time=0.0)#

Bases: Label, str

A string-valued label.

A Label for the special case when only a name is present (no state-space-labels). We create this as a separate class so that we can use the string hash function in a “hardcoded” way - if we put switching logic in __hash__ the hashing gets much slower.

Creates a new Model-item label, which is divided into a simple string label and a tuple specifying the part of the Hilbert space upon which the item acts (often just qubit indices).

Parameters:

name (str) – The item name. E.g., ‘CNOT’ or ‘H’.
state_space_labels (list or tuple, optional) – A list or tuple that identifies which sectors/parts of the Hilbert space is acted upon. In many cases, this is a list of integers specifying the qubits on which a gate acts, when the ordering in the list defines the ‘direction’ of the gate. If something other than a list or tuple is passed, a single-element tuple is created containing the passed object.
time (float) – The time at which this label occurs (can be relative or absolute)
args (iterable of hashable types, optional) – A list of “arguments” for this label. Having arguments makes the Label even more resemble a function call, and supplies parameters for the object (often a gate or layer operation) being labeled that are fixed at circuit-creation time (i.e. are not optimized over). For example, the angle of a continuously-variable X-rotation gate could be an argument of a gate label, and one might create a label: Label(‘Gx’, (0,), args=(pi/3,))

Return type:

LabelStr

Methods

`__init__`()
`capitalize`()	Return a capitalized version of the string.
`casefold`()	Return a version of the string suitable for caseless comparisons.
`center`(width[, fillchar])	Return a centered string of length width.
`collect_args`()	Gather all of the arguments of the components including this Label's arguments.
`concat`(other)	Combine two labels together so that they are one label which could be a single layer.
`copy`()
`count`(sub[, start[, end]])	Return the number of non-overlapping occurrences of substring sub in string S[start:end].
`encode`([encoding, errors])	Encode the string using the codec registered for encoding.
`endswith`(suffix[, start[, end]])	Return True if S ends with the specified suffix, False otherwise.
`expand_subcircuits`()	Expand any sub-circuits within this label.
`expandtabs`([tabsize])	Return a copy where all tab characters are expanded using spaces.
`find`(sub[, start[, end]])	Return the lowest index in S where substring sub is found, such that sub is contained within S[start:end].
`format`(args, *kwargs)	Return a formatted version of S, using substitutions from args and kwargs.
`format_map`(mapping)	Return a formatted version of S, using substitutions from mapping.
`has_prefix`(prefix[, typ])	Whether this label has the given prefix.
`index`(sub[, start[, end]])	Return the lowest index in S where substring sub is found, such that sub is contained within S[start:end].
`init`(name[, time])	Creates a new Model-item label, which is just a simple string label.
`isalnum`()	Return True if the string is an alpha-numeric string, False otherwise.
`isalpha`()	Return True if the string is an alphabetic string, False otherwise.
`isascii`()	Return True if all characters in the string are ASCII, False otherwise.
`isdecimal`()	Return True if the string is a decimal string, False otherwise.
`isdigit`()	Return True if the string is a digit string, False otherwise.
`isidentifier`()	Return True if the string is a valid Python identifier, False otherwise.
`islower`()	Return True if the string is a lowercase string, False otherwise.
`isnumeric`()	Return True if the string is a numeric string, False otherwise.
`isprintable`()	Return True if the string is printable, False otherwise.
`isspace`()	Return True if the string is a whitespace string, False otherwise.
`istitle`()	Return True if the string is a title-cased string, False otherwise.
`isupper`()	Return True if the string is an uppercase string, False otherwise.
`join`(iterable, /)	Concatenate any number of strings.
`ljust`(width[, fillchar])	Return a left-justified string of length width.
`lower`()	Return a copy of the string converted to lowercase.
`lstrip`([chars])	Return a copy of the string with leading whitespace removed.
`maketrans`	Return a translation table usable for str.translate().
`map_state_space_labels`(mapper)	Apply a mapping to this Label's state-space (qubit) labels.
`partition`(sep, /)	Partition the string into three parts using the given separator.
`removeprefix`(prefix, /)	Return a str with the given prefix string removed if present.
`removesuffix`(suffix, /)	Return a str with the given suffix string removed if present.
`replace`(old, new[, count])	Return a copy with all occurrences of substring old replaced by new.
`replace_name`(oldname, newname)	Returns a label with oldname replaced by newname.
`rfind`(sub[, start[, end]])	Return the highest index in S where substring sub is found, such that sub is contained within S[start:end].
`rindex`(sub[, start[, end]])	Return the highest index in S where substring sub is found, such that sub is contained within S[start:end].
`rjust`(width[, fillchar])	Return a right-justified string of length width.
`rpartition`(sep, /)	Partition the string into three parts using the given separator.
`rsplit`([sep, maxsplit])	Return a list of the substrings in the string, using sep as the separator string.
`rstrip`([chars])	Return a copy of the string with trailing whitespace removed.
`split`([sep, maxsplit])	Return a list of the substrings in the string, using sep as the separator string.
`splitlines`([keepends])	Return a list of the lines in the string, breaking at line boundaries.
`startswith`(prefix[, start[, end]])	Return True if S starts with the specified prefix, False otherwise.
`strip`([chars])	Return a copy of the string with leading and trailing whitespace removed.
`strip_args`()	Return a Label which does not include the arguments.
`swapcase`()	Convert uppercase characters to lowercase and lowercase characters to uppercase.
`title`()	Return a version of the string where each word is titlecased.
`to_native`()	Returns this label as native python types.
`translate`(table, /)	Replace each character in the string using the given translation table.
`upper`()	Return a copy of the string converted to uppercase.
`with_sorted_inner_labels`()	Returns self if either (1) we aren't a LabelTupTup or (2) we are a LabelTupTup, but one or more inner Label objects have sslbls == None.
`zfill`(width, /)	Pad a numeric string with zeros on the left, to fill a field of the given width.

Attributes

`IS_SIMPLE`
`args`	This label's arguments.
`components`	The sub-label components of this label, or just (self,) if no sub-labels exist.
`depth`	The depth of this label, viewed as a sub-circuit.
`has_nontrivial_components`	Checks if this Label may be used to store other `Label`s.
`is_simple`	Whether this is a "simple" (opaque w/a true name, from a circuit perspective) label or not.
`is_sorted`	There is only ever one gate recognized by this label.
`name`	This label's name (a string).
`num_qubits`	The number of qubits this label "acts" on (an integer).
`qubits`	An alias for sslbls, since commonly these are just qubit indices.
`reps`	Number of repetitions (of this label's components) that this label represents.
`sslbls`	This label's state-space labels, often qubit labels (a tuple).
`time`

capitalize()#

Return a capitalized version of the string.

More specifically, make the first character have upper case and the rest lower case.

casefold()#: Return a version of the string suitable for caseless comparisons.

center(width, fillchar=' ', /)#

Return a centered string of length width.

Padding is done using the specified fill character (default is a space).

collect_args()#

Gather all of the arguments of the components including this Label’s arguments.

Return type:: tuple

concat(other)#: Combine two labels together so that they are one label which could be a single layer.

count(sub[, start[, end]]) → int#: Return the number of non-overlapping occurrences of substring sub in string S[start:end]. Optional arguments start and end are interpreted as in slice notation.

encode(encoding='utf-8', errors='strict')#

Encode the string using the codec registered for encoding.

encoding: The encoding in which to encode the string.
errors: The error handling scheme to use for encoding errors. The default is ‘strict’ meaning that encoding errors raise a UnicodeEncodeError. Other possible values are ‘ignore’, ‘replace’ and ‘xmlcharrefreplace’ as well as any other name registered with codecs.register_error that can handle UnicodeEncodeErrors.

endswith(suffix[, start[, end]]) → bool#: Return True if S ends with the specified suffix, False otherwise. With optional start, test S beginning at that position. With optional end, stop comparing S at that position. suffix can also be a tuple of strings to try.

expand_subcircuits()#

Expand any sub-circuits within this label.

Returns a list of component labels which doesn’t include any CircuitLabel labels. This effectively expands any “boxes” or “exponentiation” within this label.

Returns:: A tuple of component Labels (none of which should be CircuitLabel objects).
Return type:: tuple

expandtabs(tabsize=8)#

Return a copy where all tab characters are expanded using spaces.

If tabsize is not given, a tab size of 8 characters is assumed.

find(sub[, start[, end]]) → int#

Return the lowest index in S where substring sub is found, such that sub is contained within S[start:end]. Optional arguments start and end are interpreted as in slice notation.

Return -1 on failure.

format(*args, **kwargs) → str#: Return a formatted version of S, using substitutions from args and kwargs. The substitutions are identified by braces (‘{’ and ‘}’).

format_map(mapping) → str#: Return a formatted version of S, using substitutions from mapping. The substitutions are identified by braces (‘{’ and ‘}’).

has_prefix(prefix, typ='all')#

Whether this label has the given prefix.

Usually used to test whether the label names a given type.

Parameters:

prefix (str) – The prefix to check for.
typ ({"any","all"}) – Whether, when there are multiple parts to the label, the prefix must occur in any or all of the parts.

Return type:

bool

index(sub[, start[, end]]) → int#

Return the lowest index in S where substring sub is found, such that sub is contained within S[start:end]. Optional arguments start and end are interpreted as in slice notation.

Raises ValueError when the substring is not found.

classmethod init(name, time=0.0)#

Creates a new Model-item label, which is just a simple string label.

Parameters:

name (str) – The item name. E.g., ‘CNOT’ or ‘H’.
time (float) – The time at which this label occurs (can be relative or absolute)

Return type:

LabelStr

isalnum()#

Return True if the string is an alpha-numeric string, False otherwise.

A string is alpha-numeric if all characters in the string are alpha-numeric and there is at least one character in the string.

isalpha()#

Return True if the string is an alphabetic string, False otherwise.

A string is alphabetic if all characters in the string are alphabetic and there is at least one character in the string.

isascii()#

Return True if all characters in the string are ASCII, False otherwise.

ASCII characters have code points in the range U+0000-U+007F. Empty string is ASCII too.

isdecimal()#

Return True if the string is a decimal string, False otherwise.

A string is a decimal string if all characters in the string are decimal and there is at least one character in the string.

isdigit()#

Return True if the string is a digit string, False otherwise.

A string is a digit string if all characters in the string are digits and there is at least one character in the string.

isidentifier()#

Return True if the string is a valid Python identifier, False otherwise.

Call keyword.iskeyword(s) to test whether string s is a reserved identifier, such as “def” or “class”.

islower()#

Return True if the string is a lowercase string, False otherwise.

A string is lowercase if all cased characters in the string are lowercase and there is at least one cased character in the string.

isnumeric()#

Return True if the string is a numeric string, False otherwise.

A string is numeric if all characters in the string are numeric and there is at least one character in the string.

isprintable()#

Return True if the string is printable, False otherwise.

A string is printable if all of its characters are considered printable in repr() or if it is empty.

isspace()#

Return True if the string is a whitespace string, False otherwise.

A string is whitespace if all characters in the string are whitespace and there is at least one character in the string.

istitle()#

Return True if the string is a title-cased string, False otherwise.

In a title-cased string, upper- and title-case characters may only follow uncased characters and lowercase characters only cased ones.

isupper()#

Return True if the string is an uppercase string, False otherwise.

A string is uppercase if all cased characters in the string are uppercase and there is at least one cased character in the string.

join(iterable, /)#

Concatenate any number of strings.

The string whose method is called is inserted in between each given string. The result is returned as a new string.

Example: ‘.’.join([‘ab’, ‘pq’, ‘rs’]) -> ‘ab.pq.rs’

ljust(width, fillchar=' ', /)#

Return a left-justified string of length width.

Padding is done using the specified fill character (default is a space).

lower()#: Return a copy of the string converted to lowercase.

lstrip(chars=None, /)#

Return a copy of the string with leading whitespace removed.

If chars is given and not None, remove characters in chars instead.

static maketrans()#

Return a translation table usable for str.translate().

If there is only one argument, it must be a dictionary mapping Unicode ordinals (integers) or characters to Unicode ordinals, strings or None. Character keys will be then converted to ordinals. If there are two arguments, they must be strings of equal length, and in the resulting dictionary, each character in x will be mapped to the character at the same position in y. If there is a third argument, it must be a string, whose characters will be mapped to None in the result.

map_state_space_labels(mapper)#

Apply a mapping to this Label’s state-space (qubit) labels.

Return a copy of this Label with all of the state-space labels (often just qubit labels) updated according to a mapping function.

For example, calling this function with mapper = {0: 1, 1: 3} on the Label “Gcnot:0:1” would return “Gcnot:1:3”.

Parameters:: mapper (dict or function) – A dictionary whose keys are the existing state-space-label values and whose value are the new labels, or a function which takes a single (existing state-space-label) argument and returns a new state-space-label.
Returns:: A new label of the same concrete type as self (e.g. a LabelTup returns a LabelTup).
Return type:: Label

partition(sep, /)#

Partition the string into three parts using the given separator.

This will search for the separator in the string. If the separator is found, returns a 3-tuple containing the part before the separator, the separator itself, and the part after it.

If the separator is not found, returns a 3-tuple containing the original string and two empty strings.

removeprefix(prefix, /)#

Return a str with the given prefix string removed if present.

If the string starts with the prefix string, return string[len(prefix):]. Otherwise, return a copy of the original string.

removesuffix(suffix, /)#

Return a str with the given suffix string removed if present.

If the string ends with the suffix string and that suffix is not empty, return string[:-len(suffix)]. Otherwise, return a copy of the original string.

replace(old, new, count=-1, /)#

Return a copy with all occurrences of substring old replaced by new.

count
Maximum number of occurrences to replace. -1 (the default value) means replace all occurrences.

If the optional argument count is given, only the first count occurrences are replaced.

replace_name(oldname, newname)#

Returns a label with oldname replaced by newname.

Parameters:

oldname (str) – Name to find.
newname (str) – Name to replace found name with.

Return type:

LabelStr

rfind(sub[, start[, end]]) → int#

Return the highest index in S where substring sub is found, such that sub is contained within S[start:end]. Optional arguments start and end are interpreted as in slice notation.

Return -1 on failure.

rindex(sub[, start[, end]]) → int#

Return the highest index in S where substring sub is found, such that sub is contained within S[start:end]. Optional arguments start and end are interpreted as in slice notation.

Raises ValueError when the substring is not found.

rjust(width, fillchar=' ', /)#

Return a right-justified string of length width.

Padding is done using the specified fill character (default is a space).

rpartition(sep, /)#

Partition the string into three parts using the given separator.

This will search for the separator in the string, starting at the end. If the separator is found, returns a 3-tuple containing the part before the separator, the separator itself, and the part after it.

If the separator is not found, returns a 3-tuple containing two empty strings and the original string.

rsplit(sep=None, maxsplit=-1)#

Return a list of the substrings in the string, using sep as the separator string.

sep
The separator used to split the string.

When set to None (the default value), will split on any whitespace character (including n r t f and spaces) and will discard empty strings from the result.

maxsplit
Maximum number of splits. -1 (the default value) means no limit.

Splitting starts at the end of the string and works to the front.

rstrip(chars=None, /)#

Return a copy of the string with trailing whitespace removed.

If chars is given and not None, remove characters in chars instead.

split(sep=None, maxsplit=-1)#

Return a list of the substrings in the string, using sep as the separator string.

sep
The separator used to split the string.

When set to None (the default value), will split on any whitespace character (including n r t f and spaces) and will discard empty strings from the result.

maxsplit
Maximum number of splits. -1 (the default value) means no limit.

Splitting starts at the front of the string and works to the end.

Note, str.split() is mainly useful for data that has been intentionally delimited. With natural text that includes punctuation, consider using the regular expression module.

splitlines(keepends=False)#

Return a list of the lines in the string, breaking at line boundaries.

Line breaks are not included in the resulting list unless keepends is given and true.

startswith(prefix[, start[, end]]) → bool#: Return True if S starts with the specified prefix, False otherwise. With optional start, test S beginning at that position. With optional end, stop comparing S at that position. prefix can also be a tuple of strings to try.

strip(chars=None, /)#

Return a copy of the string with leading and trailing whitespace removed.

If chars is given and not None, remove characters in chars instead.

strip_args()#: Return a Label which does not include the arguments.

swapcase()#: Convert uppercase characters to lowercase and lowercase characters to uppercase.

title()#

Return a version of the string where each word is titlecased.

More specifically, words start with uppercased characters and all remaining cased characters have lower case.

to_native()#

Returns this label as native python types.

Useful for faster serialization. The returned value is guaranteed to be roundtrippable back through the Label constructor, satisfying: Label(lbl.to_native()) == lbl.

Returns:: The native representation of this label (e.g., a string or a tuple of native types).
Return type:: NativeLabel

translate(table, /)#

Replace each character in the string using the given translation table.

table
Translation table, which must be a mapping of Unicode ordinals to Unicode ordinals, strings, or None.

The table must implement lookup/indexing via __getitem__, for instance a dictionary or list. If this operation raises LookupError, the character is left untouched. Characters mapped to None are deleted.

upper()#: Return a copy of the string converted to uppercase.

with_sorted_inner_labels()#

Returns self if either (1) we aren’t a LabelTupTup or (2) we are a LabelTupTup, but one or more inner Label objects have sslbls == None.

In all other situations, we return a LabelTupTup whose inner labels are sorted according to their sslbls. This may raise an error if any of the sslbls are not comparable to one another.

Note that we are sorting in increasing order of the first qubit that the label acts on and respect the order of the sslbls for each label.

Return type:: LabelTup | LabelTupWithArgs | LabelTupWithTime | LabelTupTup | LabelTupTupWithArgs | LabelTupTupWithTime | LabelStr | CircuitLabel

zfill(width, /)#

Pad a numeric string with zeros on the left, to fill a field of the given width.

The string is never truncated.

property args: tuple#: This label’s arguments.

property components: tuple[LabelStr]#: The sub-label components of this label, or just (self,) if no sub-labels exist.

property depth: int#: The depth of this label, viewed as a sub-circuit.

property has_nontrivial_components: bool#: Checks if this Label may be used to store other `Label`s.

property is_simple: bool#: Whether this is a “simple” (opaque w/a true name, from a circuit perspective) label or not.

property is_sorted: Literal[True]#: There is only ever one gate recognized by this label.

property name: str#: This label’s name (a string).

property num_qubits: int | None#: The number of qubits this label “acts” on (an integer). None if self.ssbls is None.

property qubits: tuple[str | Integral | int, ...] | None#: An alias for sslbls, since commonly these are just qubit indices. (a tuple)

property reps: int#: Number of repetitions (of this label’s components) that this label represents.

property sslbls: None#: This label’s state-space labels, often qubit labels (a tuple).

pygsti.baseobjs.label.LabelStr

Contents

pygsti.baseobjs.label.LabelStr#