[英]Extracting multiple substring from a string
我有一個復雜的字符串,想嘗試從中提取多個子字符串。
該字符串由一組項目組成,以逗號分隔。 每個項目都有一對用括號括起來的單詞的標識符(id-n)。 我只想在括號內的單詞末尾附加一個數字(例如“ This-1”)。 該數字實際上指示提取后單詞應如何變位的位置。
#Example of how the individual items would look like
id1(attr1, is-2) #The number 2 here indicates word 'is' should be in position 2
id2(attr2, This-1) #The number 1 here indicates word 'This' should be in position 1
id3(attr3, an-3) #The number 3 here indicates word 'an' should be in position 3
id4(attr4, example-4) #The number 4 here indicates word 'example' should be in position 4
id5(attr5, example-4) #This is a duplicate of the word 'example'
#Example of string - this is how the string with the items looks like
string = "id1(attr1, is-1), id2(attr2, This-2), id3(attr3, an-3), id4(attr4, example-4), id5(atttr5, example-4)"
#This is how the result should look after extraction
result = 'This is an example'
有沒有更簡單的方法可以做到這一點? 正則表達式不適用於我。
為什么不使用正則表達式? 這可行。
In [44]: s = "id1(attr1, is-2), id2(attr2, This-1), id3(attr3, an-3), id4(attr4, example-4), id5(atttr5, example-4)"
In [45]: z = [(m.group(2), m.group(1)) for m in re.finditer(r'(\w+)-(\d+)\)', s)]
In [46]: [x for y, x in sorted(set(z))]
Out[46]: ['This', 'is', 'an', 'example']
一個簡單/天真的方法:
>>> z = [x.split(',')[1].strip().strip(')') for x in s.split('),')]
>>> d = defaultdict(list)
>>> for i in z:
... b = i.split('-')
... d[b[1]].append(b[0])
...
>>> ' '.join(' '.join(d[t]) for t in sorted(d.keys(), key=int))
'is This an example example'
example
,在示例字符串中有重復的位置,這就是為什么在代碼中重復example
原因。
但是,您的樣本也不符合您的要求-但這是根據您的描述的結果。 單詞按照其位置指示符排列。
現在,如果要消除重復項:
>>> ' '.join(e for t in sorted(d.keys(), key=int) for e in set(d[t]))
'is This an example'
好吧,這呢:
sample = "id1(attr1, is-2), id2(attr2, This-1),
id3(attr3, an-3), id4(attr4, example-4), id5(atttr5, example-4)"
def make_cryssie_happy(s):
words = {} # we will use this dict later
ll = s.split(',')[1::2]
# we only want items like This-1, an-3, etc.
for item in ll:
tt = item.replace(')','').lstrip()
(word, pos) = tt.split('-')
words[pos] = word
# there can only be one word at a particular position
# using a dict with the numbers as positions keys
# is an alternative to using sets
res = [words[i] for i in sorted(words)]
# sort the keys, dicts are unsorted!
# create a list of the values of the dict in sorted order
return ' '.join(res)
# return a nice string
print make_cryssie_happy(sample)
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.