Python学习笔记(20140508)

分类： Python/Ruby

不明白为什么以下语句：

while True:
for i in ["/","-","|","\\","|"]:
print "%s\b" % i,

跟

while True:
for i in ["/","-","|","\\","|"]:
print "%s\r" % i,

的输出显示跟自己预期相反。

根据下表，

Escape	What it does.
\\	Backslash ()
\'	Single-quote (')
\"	Double-quote (")
\a	ASCII bell (BEL)
\b	ASCII backspace (BS)
\f	ASCII formfeed (FF)
\n	ASCII linefeed (LF)
\N{name}	Character named name in the Unicode database (Unicode only)
\r ASCII	Carriage Return (CR)
\t ASCII	Horizontal Tab (TAB)
\uxxxx	Character with 16-bit hex value xxxx (Unicode only)
\Uxxxxxxxx	Character with 32-bit hex value xxxxxxxx (Unicode only)
\v	ASCII vertical tab (VT)
\ooo	Character with octal value ooo
\xhh	Character with hex value hh

\r 为回车， \b 为退格，那么我预期输出前者是显示无限排

/ - \ |
/ - \ |
/ - \ |

后者预期输出看起来是 “旋转的杆”。

然而实际结果跟我预测不一样。

这问题先码起来，跳过，以后明白再来思考。