python_打印pstree效果

from subprocess import PIPE,Popen
import shlex

def pstree():
cmd = 'ps ax -o pid,ppid,command'
sub = Popen(shlex.split(cmd),stdout=PIPE)
return sub.stdout.readlines()[1:]

def parse_ps(string):
list_ps = []
for i in string:
l = i.split()
ps = {'pid':int(l[0]),'ppid':int(l[1]),'command':' '.join(l[2:])}
list_ps.append(ps)
return list_ps
def show(pid,d,depth=3):
show_root = [ i for i in d if i['pid'] == pid ][0]
print '-'*depth,show_root['pid'],show_root['ppid'],show_root['command']
show_child = [ i for i in d if i['ppid'] == pid ]
depth += 3
for i in show_child:
show(i['pid'],d,depth)

if __name__ == '__main__':
show(1,parse_ps(pstree()),3)