flush parameter is used to flush (clear) the internal buffer/stream (or we can say it is used to flush the output stream), it has two values "False" and "True".

flush参数用于刷新 (清除)内部缓冲区/流(或者可以说它用于刷新输出流 )，它具有两个值“ False”和“ True”。

"False" is the default value i.e. if we don't use the flush parameter – then flushing of the stream will be False. If we specify "True" – stream flushes.

默认值为“ False”，即，如果我们不使用flush参数 ，则流的刷新将为False。 如果我们指定“ True” –流刷新。

Output to a print() function is buffered, flushing the print() makes sure that the output that is buffered goes to the destination.

缓冲输出到print()函数的内容，刷新print()可以确保缓冲的输出到达目的地。

Note: "flush" is available in Python 3.x or later versions.

注意： “ flush”在Python 3.x或更高版本中可用。

Syntax:

句法：

print(argument1, argument2, ..., flush = value)

在print()中带有'flush'参数的Python示例 (Python examples with 'flush' parameter in print())

See, the below program carefully and understand the difference. print() function prints the text with a newline and when a newline is found output is done. Here, in the above program, we are using the end parameter to disable the newline character. The output will not display for 5 seconds. Once the program's execution is reached to the sleep() statement, the text will be printed.

请仔细看下面的程序，并了解它们之间的区别。 print()函数用换行符打印文本，找到换行符后即完成输出。 在这里，在上面的程序中，我们使用end参数禁用换行符。 输出将不会显示5秒钟 。 一旦程序的执行到达sleep()语句，将打印文本。

from time import sleep

# output is not flushed here
print("Hello, world!", end='')
sleep(5)
print("Bye!!!")

Output:

输出：

Hello, world!Bye!!!

Hopefully, you noticed something is wrong. Yes! "Hello, world!" and "Bye!!!" are printing together.

希望您注意到有问题。 是! “你好，世界！” 和“再见！！！” 正在一起打印 。

To fix this issue, specify the flush parameter with the "True" value. If it is true, the stream will be flushed.

要解决此问题，请使用“ True”值指定flush参数 。 如果为true，则将刷新流。

from time import sleep

# output is flushed here
print("Hello, world!", end='', flush= True)
sleep(5)
print("Bye!!!")

Output:

输出：

Hello, world!Bye!!!

Now, when you run the program "Hello, world!" will be printed first and then after 5 seconds "Bye!!!" will be printed.

现在，当您运行程序“ Hello，world！”时 将首先打印，然后在5秒钟后打印“再见！！” 将被打印 。

翻译自: https://www.includehelp.com/python/flush-parameter-in-python-with-print-function.aspx