Use the following link to read more about reload built-in function. Please find sample below:
import controls.grid
reload(controls.grid)
Note that reload is 'Reload a previously imported module. The argument must be a module object, so it must have been successfully imported before.' and 'When a module is reloaded, its dictionary (containing the module’s global variables) is retained. Redefinitions of names will override the old definitions, so this is generally not a problem. If the new version of a module does not define a name that was defined by the old version, the old definition remains.'