n.jobs: int, optional (default: 1) The number of jobs to use for the computation. If -1 all CPUs are used. If 1 is given, no parallel computing code is used at all, which is useful for debugging. For n.jobs below -1, (n.cpus + 1 + n.jobs) are used. Thus for n.jobs = -2, all CPUs but one are used
From the documentation:
n.jobs: int, optional (default: 1) The number of jobs to use for the computation. If -1 all CPUs are used. If 1 is given, no parallel computing code is used at all, which is useful for debugging. For n.jobs below -1, (n.cpus + 1 + n.jobs) are used. Thus for n.jobs = -2, all CPUs but one are used