pyquil.quil¶
Module for creating and defining Quil programs.

class
pyquil.quil.
Program
(*instructions)¶ Bases:
object

dagger
(inv_dict=None, suffix='INV')¶ Creates the conjugate transpose of the Quil program. The program must not contain any irreversible actions (measurement, control flow, qubit allocation).
Returns: The Quil program’s inverse Return type: Program

defgate
(name, matrix, parameters=None)¶ Define a new static gate.
Note
The matrix elements along each axis are ordered by bitstring. For two qubits the order is
00, 01, 10, 11
, where the the bits are ordered in reverse by the qubit index, i.e., for qubits 0 and 1 the bitstring01
indicates that qubit 0 is in the state 1. See also the related documentation section in the QVM Overview.Parameters:  name (string) – The name of the gate.
 matrix (arraylike) – List of lists or Numpy 2d array.
 parameters (list) – list of parameters that are used in this gate
Returns: The Program instance.
Return type:

define_noisy_gate
(name, qubit_indices, kraus_ops)¶ Overload a static ideal gate with a noisy one defined in terms of a Kraus map.
Note
The matrix elements along each axis are ordered by bitstring. For two qubits the order is
00, 01, 10, 11
, where the the bits are ordered in reverse by the qubit index, i.e., for qubits 0 and 1 the bitstring01
indicates that qubit 0 is in the state 1. See also the related documentation section in the QVM Overview.Parameters:  name (str) – The name of the gate.
 qubit_indices (tuplelist) – The qubits it acts on.
 kraus_ops (tuplelist) – The Kraus operators.
Returns: The Program instance
Return type:

define_noisy_readout
(qubit_index, p00, p11)¶ For this program define a classical bit flip readout error channel parametrized by
p00
andp11
. This models the effect of thermal noise that corrupts the readout signal after it has interrogated the qubit.Parameters: Returns: The Program with an appended READOUTPOVM Pragma.
Return type:

defined_gates
¶ A list of defined gates on the program.

gate
(name, params, qubits)¶ Add a gate to the program.
Note
The matrix elements along each axis are ordered by bitstring. For two qubits the order is
00, 01, 10, 11
, where the the bits are ordered in reverse by the qubit index, i.e., for qubits 0 and 1 the bitstring01
indicates that qubit 0 is in the state 1. See also the related documentation section in the QVM Overview.Parameters:  name (string) – The name of the gate.
 params (list) – Parameters to send to the gate.
 qubits (list) – Qubits that the gate operates on.
Returns: The Program instance
Return type:

get_qubits
()¶ Returns all of the qubit indices used in this program, including gate applications and allocated qubits. e.g.
>>> p = Program() >>> p.inst(("H", 1)) >>> p.get_qubits() {1} >>> q = p.alloc() >>> p.inst(H(q)) >>> len(p.get_qubits()) 2
Returns: A set of all the qubit indices used in this program Return type: set

if_then
(classical_reg, if_program, else_program=None)¶ If the classical register at index classical reg is 1, run if_program, else run else_program.
Equivalent to the following construction:
IF [c]: instrA... ELSE: instrB... => JUMPWHEN @THEN [c] instrB... JUMP @END LABEL @THEN instrA... LABEL @END
Parameters: Returns: The Quil Program with the branching instructions added.
Return type:

inst
(*instructions)¶ Mutates the Program object by appending new instructions.
This function accepts a number of different valid forms, e.g.
>>> p = Program() >>> p.inst(H(0)) # A single instruction >>> p.inst(H(0), H(1)) # Multiple instructions >>> p.inst([H(0), H(1)]) # A list of instructions >>> p.inst(("H", 1)) # A tuple representing an instruction >>> p.inst("H 0") # A string representing an instruction >>> q = Program() >>> p.inst(q) # Another program
 It can also be chained:
>>> p = Program() >>> p.inst(H(0)).inst(H(1))
Parameters: instructions – A list of Instruction objects, e.g. Gates Returns: self for method chaining

instructions
¶ Fill in any placeholders and return a list of quil AbstractInstructions.

is_protoquil
()¶ Protoquil programs may only contain gates, no classical instructions and no jumps.
Returns: True if the Program is Protoquil, False otherwise

measure
(qubit_index, classical_reg=None)¶ Measures a qubit at qubit_index and puts the result in classical_reg
Parameters: Returns: The Quil Program with the appropriate measure instruction appended, e.g. MEASURE 0 [1]
Return type:

measure_all
(*qubit_reg_pairs)¶ Measures many qubits into their specified classical bits, in the order they were entered.
Parameters: qubit_reg_pairs (Tuple) – Tuples of qubit indices paired with classical bits. Returns: The Quil Program with the appropriate measure instructions appended, e.g. MEASURE 0 [1] MEASURE 1 [2] MEASURE 2 [3]
Return type: Program

no_noise
()¶ Prevent a noisy gate definition from being applied to the immediately following Gate instruction.
Returns: Program

out
()¶ Converts the Quil program to a readable string.
Returns: String form of a program Return type: string

while_do
(classical_reg, q_program)¶ While a classical register at index classical_reg is 1, loop q_program
Equivalent to the following construction:
WHILE [c]: instr... => LABEL @START JUMPUNLESS @END [c] instr... JUMP @START LABEL @END
Parameters: Returns: The Quil Program with the loop instructions added.
Return type:


pyquil.quil.
merge_programs
(prog_list)¶ Merges a list of pyQuil programs into a single one by appending them in sequence
Parameters: prog_list (list) – A list of pyquil programs Returns: a single pyQuil program Return type: Program

pyquil.quil.
shift_quantum_gates
(program, shift_offset)¶ Shifts a quantum gates in a quil program so that all qubit indices change by a certain offset :param program: a pyquil Program :param shift_offset: integer :return: pyquil Program with shifted qubit indices