I have an assignment said that to create a findString function that accept 2 string which are 'target' and 'query', and that returns a list of all indices in target where query appears. If target does not contain query, return an empty list.
For example: findString(‘attaggtttattgg’,’gg’)
return:
[4,12]
I dont know how to start off with this function writing at all. Please help me everyone. Thank you so much!!!
since an answer has already been given:
def find_matches(strng, substrng):
substrg_len = len(substr)
return [i for i in range(len(strg) + 1 - substrg_len)
if strg[i:i+substrg_len] == substrg]
def find_string(search, needle): start = -1 results = []
while start + 1< len(search): start = search.find(needle, start +1) if start == -1: break results.append(start ) return results
Here are a couple of hints to get you started.
target.find(query) will return the index of query in target. If query is not found, it will return -1.
A string can be sliced. target[pos:] will give you a substring of target starting from pos.
This may require some error handling:
def find_allPatterns(strVal, strSub):
listPos = []
strTemp = strVal
while True:
try:
posInStr = strTemp.index(strSub)
except ValueError:
posInStr = None
if posInStr:
listPos.append(posInStr)
subpos = posInStr + len(strSub)
strTemp = strTemp[subpos:]
else:
break
return listPos
print find_allPatterns('attaggtttattgg', 'gg')
Output:
[4, 6]
