如何使用python在预处理的句子中取回单词的原始位置？

Question

I am trying to get a sentence from User and preprocessing the same to remove special characters using regex at backend then I need to send back the position of a particular word in order to highlight that word to User, but facing conflict as the position of original and the preprocessed sentence are different.

Is there any best method to solve the above issue using Python?

For example:

import re

def text_preprocessing(input_text, string_to_find):

    print("Original text is:", input_data)
    cleaned_text = [re.sub('[^a-zA-Z0-9#.+]', " ", input_data)]
    cleaned_text = [re.sub(' +', " ", text) for text in cleaned_text]
    for cleaned_text in cleaned_text:  # just to convert list to string
        print("preprocessed text is:", cleaned_text)
        position = cleaned_text.find(string_to_find)
        position = [position, position + len(string_to_find)]
        return position

input_text = 'Hi! Hello'
string_to_find = 'Hello'
position = text_preprocessing(input_text, string_to_find)
print(position)

Actual Output

Original text is: Hi! Hello
preprocessed text is: Hi Hello
[3, 8]

original sentence = 'Hi! Hello'

Preprocessed sentence = 'Hi Hello' (just removed '!' symbol)

In case i need to highlight the word "Hello" I just returning the position from backend as (3,8) but the actual position in UI is (4, 9)

Expected Output

Original text is: Hi! Hello
preprocessed text is: Hi Hello
[4, 9]

---

OS: windows 10, Python 3.7, used regex for preprocessing

Answer 1

The first character in a string is at position 0 , then, Hello is at position 3 in the string Hi Hello .

• H is at 0
• i is at 1
• is at 2
• H is at 3
• e is at 4
• and so on ...