Tutorials
Libraries
API References
qiskit.circuit
qiskit.compiler
qiskit.execute
qiskit.visualization
qiskit.converters
qiskit.assembler
qiskit.dagcircuit
qiskit.extensions
qiskit.providers.basicaer
qiskit.providers
qiskit.providers.models
qiskit.pulse
qiskit.scheduler
qiskit.qasm
qiskit.qobj
qiskit.quantum_info
qiskit.result
qiskit.tools
qiskit.tools.jupyter
qiskit.transpiler
qiskit.transpiler.passes
qiskit.transpiler.preset_passmanagers
qiskit.validation
Troubleshooting
Return the total number of qubits used by the circuit. num_qubits() replaces former use of width(). DAGCircuit.width() now returns qubits + clbits for consistency with Circuit.width() [qiskit-terra #2564].