Python：提取与字符串中的正则表达式匹配的子字符串

Question

I am trying to fetch some database details from wp-config.php file. Unfortunately I stick on the part where I have the line that contains the DB_NAME and I could not extract the database_name only from the following:

define('DB_NAME', 'database_name');

Help is much appreciated!

Answer 1

Iterate over each line and then apply re.search like below.

>>> x = "define('DB_NAME', 'database_name');"
>>> re.search(r"define\('DB_NAME',\s*'([^']*)'\);", x).group(1)
'database_name'

or

for line in f:
    if 'DB_NAME' in line:
        print line.split("'")[3]