字符串中短語之前的前序單詞數

Question

假設我有一個短語列表：

list = ['new york', 'school', 'new']

和一個字符串

text = 'i am going to a school in new york and therefore i have to buy a new uniform to go to new york'

我想找到每個短語之前的單詞數量（僅針對首次出現），即輸出應為：

new york = 7
school = 5
new = 7

知道我怎樣才能有效地做到這一點嗎？

Answer 1

幼稚的方法，不考慮任何性能或NLP：

lst = ['new york', 'school', 'new']  # do not use 'list' as a name
text = 'i am going to a school in new york and therefore i have to buy a new uniform to go to new york'

{p: len(text[:text.find(p)].strip().split()) for p in lst}
# {'new york': 7, 'school': 5, 'new': 7}

Answer 2

使用count和index ：

lst = ['new york', 'school', 'new']
text = 'i am going to a school in new york and therefore i have to buy a new uniform to go to new york'

for x in lst:
    print(f"{x} = {text.count(' ', 0, text.index(x))}")

# new york = 7
# school = 5                                                   
# new = 7

從開始count ，直到遇到詞組的首次出現為止， count計算text空格，該空格與該詞組前面的單詞數相同。

Answer 3

lst = ['new york', 'school', 'new']
text = 'i am going to a school in new york and therefore i have to buy a new uniform to go to new york'

這將為您提供要搜索其計數和字符串數的字符串

for x in lst:
    print(x +": "+str(len(text[0:text.index(x)].split(' ')) -1))