从python中的字符串中提取未知子字符串[重复]

Question

我有以下字符串：

HTTP/1.1 200 OK
CACHE-CONTROL: max-age=100
EXT:
LOCATION: string to be extracted followed by a \n
SERVER: FreeRTOS/6.0.5, UPnP/1.0, IpBridge/0.1
ST: urn:schemas-upnp-org:device:basic:1
USN: uuid:2f402f80-da50-11e1-9b23-0017881892ca

我想提取 LOCATION: 之后的任何内容，直到新行。

我不能使用 substring in string 方法，因为 'LOCATION: ` 后面的内容可能会改变。

我尝试将此字符串放入字典，然后检索“LOCATION”键的值。但这似乎是在浪费内存和处理时间。因为除了那个值之外，字典对我来说毫无用处。如果字符串太大，字典的大小也可能会变大

有没有其他方法可以提取 'LOCATION: ` 之后的内容，直到 '\n' ？？

Answer 1

您使用正则表达式提取字符串

>>> import re
>>> string = """HTTP/1.1 200 OK
... CACHE-CONTROL: max-age=100
... EXT:
... LOCATION: http://129.94.5.95:80/description.xml
... SERVER: FreeRTOS/6.0.5, UPnP/1.0, IpBridge/0.1
... ST: urn:schemas-upnp-org:device:basic:1
... USN: uuid:2f402f80-da50-11e1-9b23-0017881892ca
... """
>>> regex = re.compile('LOCATION: (.*?)\n')
>>> m = regex.search(string)
>>> if m:
...     print m.group(1)
http://129.94.5.95:80/description.xml

Answer 2

您可以在换行符上拆分整个字符串。然后检查每一行是否开始 与LOCATION。如果它确实打印剩余的行。

string = """HTTP/1.1 200 OK
CACHE-CONTROL: max-age=100
EXT:
LOCATION: http://129.94.5.95:80/description.xml
SERVER: FreeRTOS/6.0.5, UPnP/1.0, IpBridge/0.1
ST: urn:schemas-upnp-org:device:basic:1
USN: uuid:2f402f80-da50-11e1-9b23-0017881892ca"""



 for line in string.split('\n'):
     if line.startswith('LOCATION'):
         print(line[10:])
         break

Out: http://129.94.5.95:80/description.xml

Answer 3

string.index(character) 是你需要的：

 mystr="HTTP/1.1 200 OK\nCACHE-CONTROL: max-age=100\nEXT:\nLOCATION: string to be extracted followed by a \nSERVER: FreeRTOS/6.0.5, UPnP/1.0, IpBridge/0.1\nST: urn:schemas-upnp-org:device:basic:1\nUSN: uuid:2f402f80-da50-11e1-9b23-0017881892ca"
search = "LOCATION"
start = mystr.index(search)+len(search)
stop = mystr.index("\n", start)
print mystr [ start : stop ]

Answer 4

您可以使用splitlines 拆分行，然后根据: 拆分各个行，将它们转换为字典，如下所示

d = dict(item.split(": ", 1) for item in data.splitlines() if ": " in item)
print d["LOCATION"]
# http://129.94.5.95:80/description.xml

要将键转换为小写字母，您可以像这样重构字典

d = dict(item.split(": ", 1) for item in data.splitlines() if ": " in item)
d = {key.lower():d[key] for key in d}
print d["location"]