1. islice(iterable, start, stop, step) :- This iterator selectively prints the values mentioned in its iterable container passed as argument. This iterator takes 4 arguments, iterable container, starting pos., ending position and step.
2. starmap(func., tuple list) :- This iterator takes a function and tuple list as argument and returns the value according to the function from each tuple of list.
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python - Sample - python code :
python tutorial - Output :
The sliced list values are : [4, 7, 10] The values acc. to function are : [1, 1, 4, 1]
3. takewhile(func, iterable) :- This iterator is opposite of dropwhile(), it prints the values till the function returns false for 1st time.
4. tee(iterator, count) :- This iterator splits the container into a number of iterators mentioned in the argument.
python - Sample - python code :
python tutorial - Output :
The list values till 1st false value are : [2, 4, 6] The iterators are : [2, 4, 6, 7, 8, 10, 20] [2, 4, 6, 7, 8, 10, 20] [2, 4, 6, 7, 8, 10, 20]
5. zip_longest( iterable1, iterable2, fillval.) :- This iterator prints the values of iterables alternatively in sequence. If one of the iterables is printed fully, remaining values are filled by the values assigned to fillvalue.
python - Sample - python code :
python tutorial - Output :
The combined values of iterables is : ('W', 'i') ('k', 'i') ('t', 'e') ('c', 'h') ('y', '_')
Combinatoric Iterators
1. product(iter1, iter2) :- This iterator prints the cartesian product of the two iterable containers passed as arguments.
2. permutations(iter, group_size) :- This iterator prints all possible permutation of all elements of iterable. The size of each permuted group is decided by group_size argument.
python - Sample - python code :
python tutorial - Output :
The cartesian product of the containers is : [('A', '1'), ('A', '2'), ('B', '1'), ('B', '2')] All the permutations of the given container is : [('W', 'T'), ('W', 'Y'), ('T', 'W'), ('T', 'Y'), ('Y', 'W'), ('Y', 'T')]
3. combinations(iterable, group_size) :- This iterator prints all the possible combinations(without replacement) of the container passed in arguments in the specified group size in sorted order.
4. combinations_with_replacement(iterable, group_size) :- This iterator prints all the possible combinations(with replacement) of the container passed in arguments in the specified group size in sorted order.
python - Sample - python code :
python tutorial - Output :
All the combination of container in sorted order(without replacement) is : [('1', '2'), ('1', '3'), ('1', '4'), ('2', '3'), ('2', '4'), ('3', '4')] All the combination of container in sorted order(with replacement) is : [('W', 'W'), ('W', 'T'), ('W', 'Y'), ('T', 'T'), ('T', 'Y'), ('Y', 'Y')]
Infinite Iterators
1. count(start, step) :- This iterator starts printing from the “start” number and prints infinitely. If steps are mentioned, the numbers are skipped else step is 1 by default.
Example :
iterator.count(5,2) prints -- 5,7,9,11...infinitely
2. cycle(iterable) :- This iterator prints all values in order from the passed container. It restarts printing from beginning again when all elements are printed in a cyclic manner.
Example :
iterator.cycle([1,2,3,4]) prints -- 1,2,3,4,1,2,3,4,1...infinitely
3. repeat(val, num) :- This iterator repeatedly prints the passed value infinite number of times. If num. is mentioned, them till that number.
python - Sample - python code :
python tutorial - Output :
Printing the numbers repeatedly : [25, 25, 25, 25]