python - python3 中的 sys.stdout.write 在字符串末尾添加 11

Question

有人可以解释为什么 sys.stdout.write() 将 11 附加到我的字符串吗？

$ python3
Python 3.4.3+ (default, Jul 28 2015, 13:17:50) 
[GCC 4.9.3] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> x = 'hello'
>>> y = 'world'
>>> msg = ''
>>> import sys
>>> msg += x
>>> msg += '\n' + y 
>>> msg
'hello\nworld'
>>> sys.stdout.write(msg)
hello
world11
>>> print(msg)
hello
world

Answer 1

它不会附加到写入的字符串中。 11这里是sys.stdout.write()的返回值，也就是写入的字符数。

参见 write :

Write the string s to the stream and return the number of characters written.

---

类似于:

>>> def foo():
...     print('something', end='')
...     return 42
...
>>> foo()
something42