今天发现了一个奇怪的现象，直接上代码

import sys
from colorama import Fore, Back, Style 

def print_example():
    print(Fore.RED+ "1. This is the first sentence")
     long_str=' Blowing in the wind'
    print(Fore.WHITE + '2. long_str =', end='')
    #print('2. long_str= ', end='')
    print( long_str,file=sys.stderr)
    print(Fore.CYAN + "3. Do they printed in right order")

print_example()

打印出来的结果并不是我设想的顺序

1. This is the first sentence
 Blowing in the wind
2. long_str =3. Do they printed in right order

为什么stderr和stdout会打印到一起呢? 我的猜想也许跟stdout, stderr的缓冲机制有关 后来发现python 3.3 后print可以加flush参数, 这样就能得到我想要的打印次序

import sys 
    from colorama import Fore, Back, Style
    def print_example(): 
        print(Fore.RED+ "1. This is the first sentence") 
         long_str=' Blowing in the wind' 
        print(Fore.WHITE + '2. long_str =', end='',flush=True) 
        #print('2. long_str= ', end='') 
        print( long_str,file=sys.stderr) 
        print(Fore.CYAN + "3. Do they printed in right order") 
    print_example() 
    打印出来如下
    1. This is the first sentence
    2. long_str = Blowing in the wind
    3. Do they printed in right order