import control as ctsys_tf = ct.tf([1], [1, 0])sys_ss = ct.tf2ss(sys_tf)sys_tf(0)        # returns (inf+0j) with divide by zero warningsys_tf(0j)       # returns (inf+nanj) with divide by zero warningsys_ss(0)        # LinAlgError: Singular matrixsys_tf.dcgain()  # returns array(inf)sys_ss.dcgain()  # returns array(nan)

sys_tf = ct.tf([1, 0], [1, 0])sys_ss = ct.tf2ss(sys_tf)sys_tf(0)        # returns (nan+0j) with invalid value warningsys_ss(0)        # returns (1+0j) [state space system is empty]sys_tf.dcgain()  # returns array(nan)sys_ss.dcgain()  # returns (1+0j) [state space system is empty]