Create a Regular Expression that matches a string representing a valid parenthesis sequence. Three types of parenthesis will be used: () [] {}. The string could also contain alphanumeric characters and spaces.

The pypi regex engine will be used that is more powerful than re. Matching with regex.match()

Should match:

()
()()
(())
{}
[]
{()}
[]
[{()}]
[{}()]
   ()
a()
(a)
()a
a ( a ) a
a
          a

Should NOT match

(
)
)(
)()(
(()
(}
{]
{(})

Notes

• empty strings or alphanumerics/spaces without parenthesis are valid matches
• You´re RegEx should not be longer than 150 characters

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