python變數加逗號,的含義

逗號,用於生成一個長度為1的元組

>>> (1)
1
>>> (1,)
(1,)
>>> 1,
(1,)

因此需要將長度為1的元組中元素提取出來可以用,簡化賦值操作

>>> a=(1,)
>>> b=a
>>> b
(1,)
>>> b,=a
>>> b
1

最後print列印變數加,實現連續列印不換行的操作在python3中行不通了

Python 3.7.3 (default, Nov 15 2019, 04:04:52) 
[Clang 11.0.0 (clang-1100.0.33.16)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> for i in range(0,5):
...     print(i)
... 
0
1
2
3
4
>>> for i in range(0,5):
...     print(i,)
... 
0
1
2
3
4