如何在选择特定的字符串python后打印先前的字符串

Question

I want to find word that appear before a keyword (specified and searched by me) and print out the result. I tried below code but it gives me after words not before...

    str = "Phone has better display, good speaker. Phone has average display"
    p1 = re.search(r"(display>=?)(.*)", str)
    if p1 is None:
       return None
    return p1.groups()

this code gives me

    , good speaker. Phone has average display

but i want only

    better,average

Answer 1

You can use a positive lookahead, with findall instead of search :

>>> p = re.compile(r'(\w+)\s+(?=display)')
>>> p.findall(str)
['better', 'average']

Answer 2

You can use a positive lookahead assertion ?= :

import re

str = "Phone has better display, good speaker. Phone has average display"
p1 = re.findall(r"(\w+)\s*(?=display)", str)
print(p1)
# ['better', 'average']

\\w means a word character.