Level 1 : Factorial sequence.


import math

class FactorialIterator:
    def __init__(self, n):
        self.n = n
        self.current = 0

    def __iter__(self):
        return self

    def __next__(self):
        if self.current > self.n:
            raise StopIteration
        value = math.factorial(self.current)
        self.current += 1
        return value

it = iter(FactorialIterator(4))
print(list(it))

Author: SandhyaR | Tags: iterator | 1859+ Python FAQs | Share
function | constructor | data-type-conversions | map-function | object-attribute | datetime.date,-datetime.time,-datetime.datetime | datetime | type-conversion | namedtuple | loop-control | datatype | conditional-statement | higher-order-function | data-structure | string-method | condition | mutable | error-handling | dictionaries | defining-functions | global-keyword | floats | string-formatting | error-handling | assignment-operators | odd-number | file_handling | attribute | error | default-arguments | docstring | asyncio | frozenset | dictionary | generators-in-python | list-vs-tuple | collection | print-statement | python-operators | syntaxerror | floating-point-precision | introduction-to-threads | recurssion | debugging | built-in-function | round | slicing | method-overloading | creating-and-starting-threads | memory-management | else | pickling--unpickling | classes | shallow-copy | class-and-inheritance | staticmethod | string-method | range | else-statement | operators | string-slicing | __all__-attribute | async | exception | benefit | arithmetic-operation | conditional-statements | sum-function | list-comprehension | operations | asyncio-module | stack | dictionary-comprehensions | overriding-methods | raise-statement | global | split | multiple-inheritance | list-mutation | static-method | parsing-with-strptime | set-operation | sets | parameter | exception-handling | list,-set,-and-dictionary-comprehensions | mathematics | handling-missing-values-(fillna,-dropna) | string | precedence | input | built-in-modules | invalid-list | assignment-operator | immutability | string-slicing | directory-operations | descriptors | version-check | boolean | python-syntax-and-structure | magic-method | comprehension | conversion | bitwise | complex-number | string-concatenation | rollback | aggregating-data-with-functools.reduce() | function-and-scope | decorator | identity-operator | comment | with-statement | syntax-error | using-map()-for-transformations | string-iteration | list-slicing | file | encapsulation | virtual-environment | goto-function | head-and-tail | zip | escape-operator | access-modifier | list | zip-function | __future__ | file-handling | namespace | counter | decimal | creating-custom-modules | recursion | interpreter | mapping-function | intering | application | reading:-read(),-readline(),-readlines() | list-comprehension | for | statement | introduction-to-multiprocessing | binary | immutable-data-type | pep | fabs-function | compute | context-manager | objects | class-and-instance-variable | list-join | global-variable | counter-function | sorted | keyword | encoding | boolean-and-non-boolean | class-decorators | thread | exponentiation | formal-and-actual-parameter | functional-programming | operand | enumerate() | choice | expand-tab | overflow | identifier | using-lists-as-stacks | binary-operation | zfill-function | deep-copy | bitwise-operator | opening-files-(open()) | bitwise-operator | loop | arbitrary-arguments-(*args,-**kwargs) | slice | methods | why-use-multiprocessing-over-threading?-(gil) | min-max-function | boolean-masking | math-copysign | random-function | python | while-else-loop | return-statement | introduction-to-python | basic | list-method | while-and-for-loop | data-types | quantifiers-(*,-+,-?,-{}) | function-argument | scientific-notation | difference-between-threads-and-processes | input-function | yield | control-flow | def | id-function | logical-operator | touples | using-assertions-(assertequal,-assertraises) | matplotlib | filter-function | membership-operators-(in,-not-in) | mysql | string-methods | swapping | name-mangling | lists | data-structures | formatting-with-strftime | writing:-write(),-writelines() | iterators | built-in-function | working-with-temporary-files-using-tempfile | collections | inherit | unit-testing | key-value-pairs | sys-module | regular-expression | string-formatting | python-django | file-handling | filter | memory | loop-control-statements | int | strings | numpy | design-principle | array | append | indentation | max-min | regex | gil | lambda-functions | pseudocode | software-design | python-history | class-and-object | match | control-statement | using-join()-and-is_alive()-methods | assert | sorting-and-ranking | __init_subclass__ | generators | list-indexing | list-methods-and-slicing | working-with-binary-files-(rb,-wb) | exception-handling | regular-expressions | logical-operator | lambda-function | functions | library | while-loop | multithreading | multiple-except-blocks | call | booleans | logical-operators | tuple-methods | mathematical-function | operator-and | walking-through-directories-using-os.walk() | global-variable | functional-programming | multiprocessing | expression | virtual-environment | round-function | min-function | update | single-inheritance | syntax | time-series-with-pandas | operator-overloading | while-loops | factorial-function | math | format | string-manipulation | identity-operators-(is,-is-not) | comparison | advanced-file-operations | type_conversion | default-mutable-argument | using-yield-in-functions | lambdas | managing-directories-with-os-and-shutil | using-the-threading-module | data-structures-in-python | thread-synchronization | arithmetic-expression | data-structure | oops | set | loops | feature | dictionary-methods | sum() | anchors-(^,-$) | built-in | list-operation | lambda | dicts | nested-loop | tuple | variable | working-with-dates-and-times | class | conditional-statement | generator | identity-operator | input-function | logical-operation | iterator | turtle | heap-memory | multiple-inheritance | type-conversion | import-method | sys | type-conversion-and-casting | command-line-parsing | literal-characters-and-special-characters | data_structure | matrix | pass | method | python_version | precedence-and-associativity | syntax-error | complex | iterable | threading | list-comprehensions | working-with-file-paths | indexing:-loc-vs-iloc | typeerror | integers | control-flow | inheritance | joining-and-merging-dataframes | matrix-list-comprehension | center | data-type | operator-or | init | destructor | implementation | postfix | dataframe-and-series-objects | version | reading-and-writing-large-files-efficiently | join | installation | indexing | integer | raise | tuples | data-type | python-repl | numeric | sorting | operator | python-module | polymorphism | oop | copy | package-management | using-os-and-pathlib-modules | reading-and-writing-files | pandas | tuple-unpacking | test-discovery | using-else-and-finally | random | module | print | filtering-and-indexing | thread-safe-data-structures-(queue.queue) ...