pipe

也跟 unix 的 pipe 一樣，下面是配合 fork 作例子：

import os, sys

r, w = os.pipe()

pid = os.fork()

if pid:         
        os.close(w)
        r = os.fdopen(r)
        txt = r.read()
        os.waitpid(pid,0)

else:
        os.close(r)
        w = os.fdopen(w,'w')
        w.write('hello from server')
        w.close()
        print 'child exit'
        sys.exit(0)
print 'all over'

fork

跟unix fork 一樣耶

import sys, os
import time

pid = os.fork()
if pid > 0:
       # child
       print "child PID %d" % pid
       for i in range(10):
               time.sleep(1)
               print "-"
       sys.exit(0)
print "parent PID %d" % pid
for j in range(10):
       time.sleep(1)
       print '+'

float to string

就是用 str( ) 就可以

fnumber = 1.23
fstring = str(fnumber)

fstring 就會是 '1.23'

substring

沒有 substring，因為和 C 一樣，直接用 [from:to] 取出

data = 'this is a test'
sub = data[3:10]

sub 會是 's is a '