正则表达式来获取[a]和[/ a]之间的字符串，不包括任何其他标签，例如[b] [/ b]

I have an input like the following

我有如下输入

[a href=https://twitter.com/suddentwilight][font][b][i]@suddentwilight[/font][/a] My POV: Rakhi Sawant hits below the belt & does anything for attention... [a href=https://twitter.com/mallikaLA][b]https://www.test.com[/b][/a] has maintained the grace/decency :)
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