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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def define_laser_variables(Nl, real_amplitudes=False, variables=None):
 r"""Return the amplitudes and frequencies of Nl fields. ([E_0^1, E_0^2], [varpi_1, varpi_2]) The amplitudes are complex by default: conjugate(E_0^1) But they can optionally be made real: E_0^1 They can also be made explicit functions of given variables: [E_0^1(t, z), E_0^2(t, z)] """

    if variables is None:
        E0 = [Symbol(r"E_0^"+str(l+1), real=real_amplitudes)
              for l in range(Nl)]
    else:
        E0 = [Function(r"E_0^"+str(l+1), real=real_amplitudes)(*variables)
              for l in range(Nl)]

    omega_laser = [Symbol(r"varpi_"+str(l+1), positive=True)
                   for l in range(Nl)]
    return E0, omega_laser