Python Regular Expressions (regex): Curly Braces ('{}')

Curly braces represent a range of the total number of instances to be matched. Where two numbers are used, they are separated by a comma and represent the minimum and maximum of the number of hits to be returned. If a single number is used (e.g., '{4}'), it represents the maximum number of hits; a minimum of zero is understood. If the braced expression is followed by a question mark, the expression matches as few hits as possible.