正则表达式是什么意思？ re.match（r“（^ [cf-qs-z] +）”，任何文件名）？

Question

我偶然发现了这段代码，但我不知道它匹配什么：

re.match(r"(^[cf-qs-z]+)", words)

Answer 1

• The fq and sz are character ranges , meaning any letter from f to q and from s to z in the alphabet, case sensitive
• c is a literal character c - no special meaning
• ^ defines the beginning of a string
• + is a quantifier , it means "one or more"
• parenthesis define a capturing group

In other words the expression would match 1 more characters that are c or in f to q or s to z range at the start of a string.

In cases like this, if you need an explanation for an existing regular expression, try pasting it to https://regex101.com , here is what it generates for this expression: https://regex101.com/r/cU0yT7/1 .