import re
content = '1bbbword'
print(re.search('(1.*)', content).group(1))
# '1bbbword'
print(re.search('(1[^虩]*)', content.replace('word', '虩')).group(1).replace('虩', 'word'))
# '1bbb'
import re
content = '1bbbword'
print(re.search('(1.*)', content).group(1))
# '1bbbword'
print(re.search('(1[^虩]*)', content.replace('word', '虩')).group(1).replace('虩', 'word'))
# '1bbb'