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Python Generator | yield, next(), iter()

🐍 A Generator in Python is a function that returns one result at a time for a list. In the example below we will look into a regular function and then we will see a Generator and understand the difference.

YIELD

The following function returns numbers between 0 and any integer you pass to the function:

def call_range(n):
    lst1 = []
    for x in range(n):
        lst1.append(x)
    return lst1

#This calls the function in for loop as well as in list form
for y in create_cubes(10):
    print(y)
create_cubes(10)

The following function returns numbers between 0 and any integer you pass to the function but one by one as it is generated:

def call_range(n):
    for x in range(n):
        yield x

for y in create_cubes(10):
    print(y)

NEXT()

Next() helps to call the next result as and when we want. Here is an example of how next can be used.

def call_range(n):
    for x in range(n):
        yield x

y = call_range(10)

next(y)

next(y)

next(y)

ITER()

iter() is used break a string or a list into its elements, that can be then accessed using next(). iter() comes to use when there is no generator with yield:

s = 'hello'

s_iter = iter(s)

next(s_iter)

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