为什么使用print函数的end参数改变输出时间？

Question

Maybe I wrote smth strange in a question title, I'l try to explain.
I'm trying to do password input as in linux-based systems (no symbols shows while you type).
I found one function that did it.

def getchar():
   import tty, termios, sys
   fd = sys.stdin.fileno()
   old_settings = termios.tcgetattr(fd)
   try:
      tty.setraw(sys.stdin.fileno())
      ch = sys.stdin.read(1)
   finally:
      termios.tcsetattr(fd, termios.TCSADRAIN, old_settings)
   return ch

pwd = ''

print('Type password:', end=' ') # HERE IS THE PROBLEM

while True:
    ch = getchar()
    if ch == '\r':
        break
    pwd += ch

print(pwd)

If I do not use end argument it looks like that:

But with end argument:

Line 'Type password:' will appear after while loop end. Why is this and what can I do?

Answer 1

By default, sys.stdout is line buffered , which means that anything written to it is buffered up until a newline is seen.

Because you replaced the standard end='\\n' with a space, no newline is seen yet and the buffer is not flushed. Set flush=True to force a buffer flush anyway :

print('Type password:', end=' ', flush=True)