为什么Python的原始字符串不能以一个反斜杠结尾 python raw字符串为什么不能以反斜杠结尾
\u4e3a\u4ec0\u4e48Python\u7684\u539f\u59cb\u5b57\u7b26\u4e32\u4e0d\u80fd\u4ee5\u4e00\u4e2a\u53cd\u659c\u6760\u7ed3\u5c3e\u8fd9\u4e2a\u8bf4\u6cd5\u5176\u5b9e\u4e0d\u597d\u3002
\u53cd\u659c\u6760\u4f1a\u7ed3\u5408\u540e\u4e00\u4e2a\u5b57\u7b26\u88ab\u89c6\u4f5c\u8f6c\u4e49\uff0c\u5982\u679c\u51fa\u73b0 \" \uff0c\u90a3\u4e48\u4f1a\u88ab\u8f6c\u4e49\u6389\uff0c\u7b49\u4e8e\u8bf4\u5b57\u7b26\u4e32\u7f3a\u4e86\u4e2a\u540e\u5f15\u53f7\u3002\u4f46\u662f\u5982\u679c\u4ee5 \\ \u7ed3\u5c3e\uff0c\u90a3\u4e48\u8fd9\u4e24\u4e2a\u5148\u88ab\u8f6c\u4e49\u6389\uff08\u673a\u5668\u4ece\u524d\u5411\u540e\u8bfb\uff0c\u770b\u5230\u53cd\u659c\u6760\u5c31\u5f00\u59cb\u8f6c\u4e49\uff09
\u8fd9\u662f\u4e00\u4e2aPython\u8bed\u6cd5\u89e3\u6790\u4e2d\u7684\u7455\u75b5\uff0c\u6ca1\u6709\u529e\u6cd5\u89e3\u51b3\uff0c\u6587\u6863\u91cc\u5df2\u7ecf\u660e\u786e\u8bf4\u660e\u4e0d\u53ef\u4ee5\u4e86
http://docs.python.org/reference/lexical_analysis.html
String quotes can be escaped with a backslash, but the backslash
remains in the string; for example, r"\"" is a valid string literal
consisting of two characters: a backslash and a double quote; r"\" is
not a valid string literal (even a raw string cannot end in an odd
number of backslashes). Specifically, a raw string cannot end in a single backslash (since the backslash would escape the following quote character).
Python\u8fd9\u4e48\u8bbe\u8ba1\u5927\u6982\u662f\u56e0\u4e3aPython\u89e3\u91ca\u5668\u5bf9.py\u6e90\u6587\u4ef6\u7684\u89e3\u6790\u8981\u6c42\u5427\u3002
\u53ef\u4ee5\u7528 r'abc'+'\\' \u7684\u5f62\u5f0f\u4ee3\u66ff\u3002
反斜杠会结合后一个字符被视作转义，如果出现
\"
，那么会被转义掉，等于说字符串缺了个后引号。但是如果以
\\
结尾，那么这两个先被转义掉（机器从前向后读，看到反斜杠就开始转义）
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