Python3 sleep() 问题
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Python3 sleep() problem
提问by roddds
I was writing a simple program on Python 3.1 and I stumbled upon this:
我在 Python 3.1 上写了一个简单的程序，我偶然发现了这个：
If I run this on the IDLE it works as intended - prints "Initializing."and then adds two dots, one after each second, and waits for input.
如果我在 IDLE 上运行它，它会按预期工作 - 打印"Initializing."然后添加两个点，每秒一个，然后等待输入。
from time import sleep
def initialize():
print('Initializing.', end='')
sleep(1)
print(" .", end='')
sleep(1)
print(" .", end='')
input()
initialize()
The problem is that when I double-click the .py to execute the file, it runs on python.exe instead of pythonw.exe, and strange things happen: it joins all the sleep()times i.e. makes me wait for 2 seconds, and then prints the whole string Initializing. . .at once. Why does this happen? Is there a way to avoid that happening in the terminal? It works fine if I use the IDLE in both windows and linux.
问题是当我双击 .py 执行文件时，它运行在 python.exe 而不是 pythonw.exe 上，奇怪的事情发生了：它一直加入，sleep()即让我等待 2 秒，然后打印Initializing. . .一次整个字符串。为什么会发生这种情况？有没有办法避免在终端中发生这种情况？如果我在 windows 和 linux 中都使用 IDLE，它工作正常。
采纳答案by John La Rooy
This is because the output is being buffered.
这是因为输出正在被缓冲。
You should add a sys.stdout.flush()after each write
您应该sys.stdout.flush()在每次写入后添加一个
回答by leoger
It sounds like the difference is that stdout is automatically being flushed in IDLE. For efficiency, programming languages often save up a bunch of print calls before writing to the screen, which is a slow process.
听起来区别在于标准输出会在空闲状态下自动刷新。为了提高效率，编程语言通常会在写入屏幕之前节省大量的打印调用，这是一个缓慢的过程。
Here's another question that has the answer you need: How to flush output of Python print?
这是另一个可以回答您需要的问题： 如何刷新 Python 打印的输出？
