Example of yield as filter

yield_from_example.py

"""
An example of using the `yield from` syntax in python 3 and a generator expression than mimics this.
"""

def yield_only_odd(i):
    '''
    Yield i if and only if i is odd.
    
    This is a generator that yields zero or one times.
    '''
    if i % 2 == 1:
        yield i
        
        
def odd_numbers(n):
    '''
    Yield odd numbers in the half open set [0,n).
    '''
    for i in range(n):
        yield from yield_only_odd(i)

# Demonstration of yield as a filter
print(list(odd_numbers(10)))

# Demonstration of the same in generator expressions
print(list(j for i in range(0, 10, 1) for j in yield_only_odd(i)))