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Given the following text description, write Python code to implement the functionality described below step by step
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Description:
 Advanced attributes
ReGraph implements a collection of data structures for representation of potentially infinite sets of attribute values, together with all the default set operations on them (such as union, intersection, inclusion test etc.)
Step1:  Define an infinite integer set
Step2:  Test if interger value is in the set
Step3:  Test if another integer set is a subset
Step4:  Find the intersection of two IntegerSet objects
Step5:  Find the union of two IntegerSet objects
Step6:  We can also find unions and intersections of integer sets with ordinary Python sets, as long as these sets contain integer values
Step7:  The following line of code with cause the AttributeSetError exception
Step8:  Now, define objects of RegexSet
Step9:  Test if strings are matched by regex's defining our RegexSet objects
Step10:  Test if one regex set is a subset of another
Step11:  Find the intersection of two regex sets
Step12:  Find the union of two regex sets
Step13:  Subtract a finite set of strings from a regex set
Step14:  The result may be not extremely readable, but we can test it in the following way
Step15:  Now, we can also wrap Python set objects into FiniteSet class provided in ReGraph.
Step16:  It allows us to apply to them any set operations from the common interface of ReGraph’s attribute sets. For example
Step17:  ReGraph provides two special classes of attribute sets
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Python Code:
from math import inf
import regraph.attribute_sets as atsets
Explanation: Advanced attributes
ReGraph implements a collection of data structures for representation of potentially infinite sets of attribute values, together with all the default set operations on them (such as union, intersection, inclusion test etc.):
FiniteSet – wrapper for Python finite sets.
RegexSet – a class for possibly infinite sets of strings given by regular expressions.
IntegerSet – a class for possibly infinite sets of integers defined by a set of disjoint intervals.
End of explanation
ints = atsets.IntegerSet({(0, 8), (11, inf)})
Explanation: Define an infinite integer set:
End of explanation
print(ints.contains(5))
print(ints.contains(9))
Explanation: Test if interger value is in the set:
End of explanation
a = atsets.IntegerSet({(0, 3), (20, 30)})
print(a.issubset(ints))
b = atsets.IntegerSet({(0, 10)})
print(b.issubset(ints))
Explanation: Test if another integer set is a subset:
End of explanation
a_and_ints = a.intersection(ints)
print(a_and_ints)
b_and_ints = b.intersection(ints)
print(b_and_ints)
Explanation: Find the intersection of two IntegerSet objects:
End of explanation
a_or_ints = a.union(ints)
print(a_or_ints)
b_or_ints = b.union(ints)
print(b_or_ints)
Explanation: Find the union of two IntegerSet objects:
End of explanation
a.union({13, 14})
print(a)
Explanation: We can also find unions and intersections of integer sets with ordinary Python sets, as long as these sets contain integer values:
End of explanation
try:
    a.union({13, 14, "a"})
except Exception as e:
    print("Error message: ", e)
    print("Type: ", type(e))
Explanation: The following line of code with cause the AttributeSetError exception:
End of explanation
words = atsets.RegexSet("[A-Za-z]+")
integers = atsets.RegexSet("\d+")
alphanums = atsets.RegexSet("[A-Za-z\d]+")
Explanation: Now, define objects of RegexSet:
End of explanation
print(words.match("42"))
print(integers.match("42"))
print(words.match("hello"))
print(integers.match("hello"))
Explanation: Test if strings are matched by regex's defining our RegexSet objects:
End of explanation
print(integers.issubset(words))
print(integers.issubset(alphanums))
Explanation: Test if one regex set is a subset of another:
End of explanation
print(integers.intersection(words))
print(integers.intersection(alphanums))
Explanation: Find the intersection of two regex sets:
End of explanation
print(integers.union(words))
Explanation: Find the union of two regex sets:
End of explanation
print(words.difference({"hi", "bye"}))
Explanation: Subtract a finite set of strings from a regex set:
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no_hi_bye = words.difference({"hi", "bye"})
print(no_hi_bye.match("hi"))
print(no_hi_bye.match("bye"))
print(no_hi_bye.match("afternoon"))
Explanation: The result may be not extremely readable, but we can test it in the following way:
End of explanation
a = atsets.FiniteSet({1, 2, 3})
Explanation: Now, we can also wrap Python set objects into FiniteSet class provided in ReGraph.
End of explanation
int_regex = atsets.RegexSet("\d+")
positive_integers = atsets.IntegerSet([(0, inf)])
print(a.issubset(int_regex))
print(a.issubset(positive_integers))
Explanation: It allows us to apply to them any set operations from the common interface of ReGraph’s attribute sets. For example:
End of explanation
univ = atsets.UniversalSet()
empty = atsets.EmptySet()
print(univ.union(empty))
print(univ.intersection(empty))
a = atsets.FiniteSet({1, 2, 3})
print(a.issubset(univ))
print(a.issubset(empty))
print(univ.intersection(a))
print(univ.union(a))
Explanation: ReGraph provides two special classes of attribute sets: UniversalSet and EmptySet, which in their essence are static classes. These classes contain all standard set theoretic operations and follow the common interface defined in the base class AttributeSet (as all previously presented attribute set classes). Consider a couple of examples illustrating the behaviour of UniversalSet and EmptySet:
End of explanation
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