python - 正则表达式 - 检测单词是否包含小写字符

Question

我正在尝试编写一个正则表达式来确定 C 中宏声明的名称是否大写：

#define MY_MACRO

为了仅检测大写单词（不考虑退格或连字符等特殊字符），我使用以下正则表达式：

"#define +[^A-Z]+"

如果我的宏完全大写，它可以工作，但如果它像这样则失败：

#define Mymacro

什么是能够确定这种情况的正则表达式？

Answer 1

To detect #define MixedCase but not match #define ALLUPPERCASE you need a negative lookahead assertion:

r'#define\s+(?![A-Z_]+\b)[A-Za-z_]+\b'

\b matches the word boundary; the place where a word ends, perhaps because of whitespace after it, or the end of the line.

The (?!..) negative lookahead assertion checks that the next word is not all uppercase, before allowing a match on a mixed-case word.

Note that I've included the _ underscore as well in the matching character class.

You may want to include digits in your macro names, they are legal, after all:

r'#define\s+(?![A-Z0-9_]+\b)\w+\b'

The second character class can then be simplified to \w, which is the same as [A-Za-z0-9_].

Answer 2

正则表达式是否必须做所有事情？您可以将所有#defines 与正则表达式匹配，然后使用一些非常简单的 Python 代码测试宏名称的大写：

macro_defn = re.compile(r'#define\s+(\w+)')
for line in code_source:
    macro_match = macro_defn.match(line)
    if macro_match:
        macro_name = macro.group(1)
        if macro_name.upper() != macro_name:
            print line