正则表达式(?:)(?=)(?!)(?<=)(?

import re
# pattern = re.compile('windows(?:2000|95)')    # ['windows2000', 'windows95']
# pattern = re.compile('windows(?=2000|95)')  # ['windows', 'windows']
# pattern = re.compile('windows(?!2000|95)')  # ['windows']
# pattern = re.compile('(?<=123)windows')     # ['windows']
# pattern = re.compile('(?<!,)windows')     # ['windows', 'windows']
pattern = re.compile('(?<![3,])windows')     # ['windows']
s = '''windows2000地方,windows95,123windows'''
print(re.findall(pattern,s))


在要提取的数据的前面的话，需要用小于号
re.search('(?<=://).*?(?=/)','https://www.amazon.fr/reviews/top-reviewers').group()
# www.amazon.fr