text = "jack最好,  jack最好的,  jack最好了,  jack是最好的"
pattern = "jack最好"

print(re.findall(pattern, text))         输出：['jack最好', 'jack最好', 'jack最好']
print(re.match(pattern, text))        输出：<re.Match object; span=(0, 6), match='jack最好'>
print(re.match(pattern, text).group())  输出：jack最好
print(re.fullmatch(pattern, text))    输出：None
print(re.search(pattern, text))        输出：<re.Match object; span=(0, 6), match='jack最好'>
print(re.search(pattern, text).group())   输出：jack最好