我如何找到两个子字符串('123STRINGabc' -> '字符串')之间的字符串?
我现在的方法是这样的:
>>> start = 'asdf=5;'
>>> end = '123jasd'
>>> s = 'asdf=5;iwantthis123jasd'
>>> print((s.split(start))[1].split(end)[0])
iwantthis
然而，这似乎非常低效且不符合python规则。有什么更好的方法来做这样的事情吗?
忘了说: 字符串可能不是以start和end开始和结束的。他们可能会有更多的字符之前和之后。
当前回答
如果你不想导入任何东西，试试字符串方法.index():
text = 'I want to find a string between two substrings'
left = 'find a '
right = 'between two'
# Output: 'string'
print(text[text.index(left)+len(left):text.index(right)])
其他回答
这是我之前在Daniweb中发布的代码片段:
# picking up piece of string between separators
# function using partition, like partition, but drops the separators
def between(left,right,s):
before,_,a = s.partition(left)
a,_,after = a.partition(right)
return before,a,after
s = "bla bla blaa <a>data</a> lsdjfasdjöf (important notice) 'Daniweb forum' tcha tcha tchaa"
print between('<a>','</a>',s)
print between('(',')',s)
print between("'","'",s)
""" Output:
('bla bla blaa ', 'data', " lsdjfasdj\xc3\xb6f (important notice) 'Daniweb forum' tcha tcha tchaa")
('bla bla blaa <a>data</a> lsdjfasdj\xc3\xb6f ', 'important notice', " 'Daniweb forum' tcha tcha tchaa")
('bla bla blaa <a>data</a> lsdjfasdj\xc3\xb6f (important notice) ', 'Daniweb forum', ' tcha tcha tchaa')
"""
start = 'asdf=5;'
end = '123jasd'
s = 'asdf=5;iwantthis123jasd'
print s[s.find(start)+len(start):s.rfind(end)]
给了
iwantthis
从Nikolaus Gradwohl的答案进一步，我需要从下面的文件内容(文件名:docker- composition .yml)中获得版本号(即0.0.2)之间('ui:'和'-'):
version: '3.1'
services:
ui:
image: repo-pkg.dev.io:21/website/ui:0.0.2-QA1
#network_mode: host
ports:
- 443:9999
ulimits:
nofile:test
这是它如何为我工作(python脚本):
import re, sys
f = open('docker-compose.yml', 'r')
lines = f.read()
result = re.search('ui:(.*)-', lines)
print result.group(1)
Result:
0.0.2
s[len(start):-len(end)]
下面是一个函数，我做了返回一个字符串(s)之间的字符串string1和string2搜索列表。
def GetListOfSubstrings(stringSubject,string1,string2):
MyList = []
intstart=0
strlength=len(stringSubject)
continueloop = 1
while(intstart < strlength and continueloop == 1):
intindex1=stringSubject.find(string1,intstart)
if(intindex1 != -1): #The substring was found, lets proceed
intindex1 = intindex1+len(string1)
intindex2 = stringSubject.find(string2,intindex1)
if(intindex2 != -1):
subsequence=stringSubject[intindex1:intindex2]
MyList.append(subsequence)
intstart=intindex2+len(string2)
else:
continueloop=0
else:
continueloop=0
return MyList
#Usage Example
mystring="s123y123o123pp123y6"
List = GetListOfSubstrings(mystring,"1","y68")
for x in range(0, len(List)):
print(List[x])
output:
mystring="s123y123o123pp123y6"
List = GetListOfSubstrings(mystring,"1","3")
for x in range(0, len(List)):
print(List[x])
output:
2
2
2
2
mystring="s123y123o123pp123y6"
List = GetListOfSubstrings(mystring,"1","y")
for x in range(0, len(List)):
print(List[x])
output:
23
23o123pp123
