Python 查找所有匹配的子字符串模式并替换子字符串
问题描述:
我想搜索一个句子是否有特定的模式.如果没有找到,什么都不做.如果找到模式,则用字符串中的另一个子字符串替换模式.
I want to search if a sentence has particular pattern or not. Do nothing if not found. If pattern found, substitute pattern with another substring in the string.
line1 = "Who acted as `` Bruce Wayne '' in the movie `` Batman Forever '' ?"
#Desired Result: Who acted as ``Bruce_Wayne'' in the movie ``Batman_Forever'' ?
#This is what I have tried..
def findSubString(raw_string, start_marker, end_marker):
start = raw_string.index(start_marker) + len(start_marker)
end = raw_string.index(end_marker, start)
return raw_string[start:end]
phrase = findSubString(line1, "``", "''")
newPhrase = phrase.strip(' ').replace(' ', '_')
line1 = line1.replace(phrase, newPhrase)
当前结果:谁在电影《永远的蝙蝠侠》中扮演了Bruce_Wayne"?
到目前为止,我设法找到了句子中的第一个出现,但没有找到下一个.如何搜索具有匹配模式的所有事件?
So far, I managed to find the first occurrence in the sentence but not the next. How to search for all occurrences with matching pattern?
答
使用正则表达式:
import re
def findSubString(raw_string, start_marker, end_marker):
return re.sub(
r'(?<={}).*?(?={})'.format(re.escape(start_marker), re.escape(end_marker)),
lambda m: m.group().strip().replace(' ', '_'),
raw_string)
line1 = "Who acted as `` Bruce Wayne '' in the movie `` Batman Forever '' ?"
line1 = findSubString(line1, "``", "''")
assert line1 == "Who acted as ``Bruce_Wayne'' in the movie ``Batman_Forever'' ?"
没有正则表达式:
def findSubString(raw_string, start_marker, end_marker):
result = []
rest = raw_string
while True:
head, sep, tail = rest.partition(start_marker)
if not sep:
break
body, sep, tail = tail.partition(end_marker)
if not sep:
break
result.append(head + start_marker + body.strip().replace(' ', '_') + end_marker)
rest = tail
result.append(rest)
return ''.join(result)