Reset Perspective Camera

import pymel.core as pm

# Check to see if perspective camera exists
if pm.objExists("|persp"):
    # Gets the perspective camera and sets it to not be a startup camera then deletes it
    perspective_camera = pm.PyNode("|persp")
    pm.camera(perspective_camera, e=True, startupCamera = False)
    pm.delete(perspective_camera)

# Creates a new camera renames it perspective, hides it, and sets it to be a startup camera
new_perspective_camera = pm.camera()
new_perspective_camera[0].rename("|persp")
new_perspective_camera[0].hide()
pm.camera(new_perspective_camera[0], e=True, startupCamera = True)
pm.reorder(new_perspective_camera[0], front=True)