python - 无法从 python 3 中的输入文件中找到子字符串

Question

我正在尝试从输入文件中查找格式。但有时如果我使用 'r' 则找不到匹配项，有时还会出现 unicode 错误。

def extract_files(filename):
    file = open(filename, 'r')
    text = file.read()
    files_match = re.findall('<Compile Include="src\asf\preprocessor\string.h">', text)
    if not files_match:
        sys.stderr.write('no match')
        sys.exit()
    for f in files_match:
        print(f)

Answer 1

看起来您正试图在<Compile Include="之后拉动所有的弦。直到 "> 。我们可以做到这一点，但请注意，这可能会在边缘情况下崩溃!

import re

def extract_files(filename):
    with open(filename,'r') as file:
        text = file.read
    matches = re.findall(r'(?<=<Compile Include=")[-.A-Za-z\\]+(?=")', text)
    # finds all pathnames that contain ONLY lowercase or uppercase letters,
    # a dash (-) or a dot (.), separated ONLY by a backslash (\)
    # terminates as soon as it finds a double-quote ("), NOT WHEN IT FINDS A
    # SINGLE QUOTE (')
    if not matches:
        sys.stderr.write("no match")
        sys.exit()
    for match in matches:
        print(match)