提取至少包含一个小写字母、一个大写字母和一个数字的6个字母？

Question

考虑字符串：

text = "aaAA23 aAAA32 32AeeeB  fjdSkjj839jl2lkjj"
pat = ?
result = re.findall(pat, text)

我正在寻找一种模式，它将给出以下结果：

["aaAA23", "aAAA32", "32Aeee", "dSkjj8"]

我是以一种天真的方式做这件事的：

pat = "[a-z]+[A-Z]+[0-9]+|[A-Z]+[a-z]+[0-9]+|[a-z]+[0-9]+[A-Z]+|[A-Z]+[0-9]+[a-z]+|[0-9]+[a-z]+[A-Z]+|[0-9]+[A-Z]+[a-z]+"

这不起作用，因为它产生：

["aaAA23", "aAAA32", "32Aeee", "Skjj839"]

怎么做

Answer 1

使用与每个所需字符类型匹配的lookahead

pat = r'(?=.{0,5}[a-z])(?=.{0,5}[A-Z])(?=.{0,5}\d)[a-zA-Z\d]{6}'

DEMO