When To Use Generators in Python https://jerrynsh.com/using-generators-in-python-the-why-the-what-and-the-when/

cprofile_examples.py

# List Comprehension
# ------------------
cProfile.run('sum([i * i for i in range(100_000_000)])')

#    5 function calls in 13.956 seconds
#    Ordered by: standard name
#    ncalls  tottime  percall  cumtime  percall filename:lineno(function)
#         1    8.442    8.442    8.442    8.442 <string>:1(<listcomp>)
#         1    0.841    0.841   13.956   13.956 <string>:1(<module>)
#         1    0.000    0.000   13.956   13.956 {built-in method builtins.exec}
#         1    4.672    4.672    4.672    4.672 {built-in method builtins.sum}
#         1    0.000    0.000    0.000    0.000 {method 'disable' of '_lsprof.Profiler' objects}


# Generator Expression
# --------------------
cProfile.run('sum((i * i for i in range(100_000_000)))')

#    100000005 function calls in 22.996 seconds
#    Ordered by: standard name
#    ncalls  tottime  percall  cumtime  percall filename:lineno(function)
# 100000001   11.745    0.000   11.745    0.000 <string>:1(<genexpr>)
#         1    0.000    0.000   22.996   22.996 <string>:1(<module>)
#         1    0.000    0.000   22.996   22.996 {built-in method builtins.exec}
#         1   11.251   11.251   22.996   22.996 {built-in method builtins.sum}
#         1    0.000    0.000    0.000    0.000 {method 'disable' of '_lsprof.Profiler' objects}

generator_fn.py

import csv
def read_csv_from_generator_fn():
    with open('large_dataset.csv', 'r') as f:
        reader = csv.reader(f)
        for row in reader:
            yield row

# To get the same output as result_1,
# We generate a list using our newly created Generator function:
result_2 = [row for row in read_csv_from_generator_fn()]

# Output same as result_1:
# [['a','b','c', ... ], ['x','y','z', ... ] ... ]

regular_fn.py

import csv
def read_csv_from_regular_fn():
    with open('large_dataset.csv', 'r') as f:
        reader = csv.reader(f)
        return [row for row in reader]

result_1 = read_csv_from_regular_fn() 

# Output:
# [['a','b','c', ... ], ['x','y','z', ... ] ... ]