# A set containing every value in range(5):
five_set = {x for x in range(5)}
print (five_set)
# Out: {0, 1, 2, 3, 4}

# A set of even numbers between 1 and 10:
even_set = {x for x in range(1, 11) if x % 2 == 0}
print (even_set)
# Out: {2, 4, 6, 8, 10}

# Unique alphabetic characters in a string of text:
text = "When in the Course of human events it becomes necessary for one people..."
new_set = {ch.lower() for ch in text if ch.isalpha()}
print (new_set)
# Out: {'i', 'e', 'b', 'c', 'r', 'p', 's', 'f', 'h', 'a', 'm', 'v', 'n', 't', 'u', 'w', 'o', 'y', 'l'}