Random String Generator
This is a string generator that takes a regular expression as argument and returns strings that match the given regular expression.
The generator supports the following features:
[Start of the character class definition]End of the character class definition?0 or 1 quantifier*0 or more quantifier+1 or more quantifier{Start min/max quantifier}End min/max quantifier|Start of an alternative branch(Start subpattern)End subpattern
Within a character class, the following subpatterns are supported:
^ Negate the class, but only if the first character
- indicates character range
In order to use it, just import generate function from regex_to_string module using the following instruction:
from regex_to_string import generate
The generate function takes 2 arguments. The first argument is the regular expression template and the other is the number of unique string we want to generate.
Some examples:
generate('/[-+]?[0-9]{1,16}[.][0-9]{1,6}/', 10)
7223329.250639
-0905733704286648.1
875.4
+868.16
4134.559
6922348437950086.1781
59558.2623
-08739804757328.9139
316759710853.75668
-440148344686.47493
'generate('/(1[0-2])|(0[1-9])(:[0-5][0-9]){2} (A|P)M/', 10)
12:12:02 PM
12:26:44 AM
11:49:15 AM
03:50:28 AM
10:53:27 AM
09:02:29 AM
09:12:31 AM
02:04:10 PM
05:37:02 PM
11:26:02 PM
Implementation Details
We have a class called StringGenerator. This class has an abstract class called Node which is inherited by the Literal and CharacterSet classes. Each of these classes implement a method called render. For Literal class, its just simple, return the literal. For the characterSet class, we render a random combination from the set of specified characters.
We have another class called Sequence which just contains a list of node objects and renders them.
We create an object of the StringGenerator class and initialize it with the regular expression template. We parse the template and form a sequence of nodes and then render each Node from the sequence.