Python获取字符串中某个字串之后的所有数据

方法一：使用re.findall函数

import re
link='magnet:?xt=urn:btih:XMRY3ETSWYKAQUGPQDZMDDM6CAC5OYQA'
res=re.findall('(?<=:btih:).*$',link)[0]
print(res)  # XMRY3ETSWYKAQUGPQDZMDDM6CAC5OYQA

方法二：索引下标再截取

link='magnet:?xt=urn:btih:XMRY3ETSWYKAQUGPQDZMDDM6CAC5OYQA' 
pos = link.index(':btih:')                    
res = link[pos+6:]
print(res)  # XMRY3ETSWYKAQUGPQDZMDDM6CAC5OYQA