qiskit/quantum_info/states/states.py
def basis_state(str_state, num):
    """
    Return a basis state ndarray.

    Args:
        str_state (string): a string representing the state.
        num (int): the number of qubits
    Returns:
        ndarray:  state(2**num) a quantum state with basis basis state.
     Raises:
        QiskitError: if the dimensions is wrong
    """
    n = int(str_state, 2)
    if num >= len(str_state):
        state = np.zeros(1 << num, dtype=complex)
        state[n] = 1
        return state
    else:
        raise QiskitError('size of bitstring is greater than num.')
def basis_state(str_state, num):
    """
    Return a basis state ndarray.

    Args:
        str_state (string): a string representing the state.
        num (int): the number of qubits
    Returns:
        ndarray:  state(2**num) a quantum state with basis basis state.
     Raises:
        QiskitError: if the dimensions is wrong
    """
    n = int(str_state, 2)
    if num >= len(str_state):
        state = np.zeros(1 << num, dtype=complex)
        state[n] = 1
        return state
    else:
        raise QiskitError('size of bitstring is greater than num.')
Return a basis state ndarray.

    Args:
        str_state (string): a string representing the state.
        num (int): the number of qubits
    Returns:
        ndarray:  state(2**num) a quantum state with basis basis state.
     Raises:
        QiskitError: if the dimensions is wrong