pymince 1.0.15

Python shredded utilities

pymince

About

pymince is a collection of useful tools that are "missing" from the Python standard library.

Installation (via pip)

pip install pymince

Tests

(env)$ pip install -r requirements.txt   # Ignore this command if it has already been executed
(env)$ pytest tests/
(env)$ pytest --cov pymince # Tests with coverge

Usage

PyModules	Tools
algorithm.py	fibonacci, luhn
boolean.py	string2bool
dates.py	irange, string2year
dictionary.py	DigestGetter, all_true_values, find_leaf_value, from_objects, frozendict
file.py	decompress, ensure_directory, is_empty_directory, match_from_zip, replace_extension
functional.py	classproperty
iterator.py	all_distinct, all_equal, all_equals, all_identical, consume, contains, grouper, has_only_one, ibool, in_all, in_any, pad_end, pad_start, replacer, splitter, uniquer, uniques
json.py	dump_into, dump_into_zip, load_from, load_from_zip
logging.py	StructuredFormatter, timed_block
retry.py	retry_if_errors, retry_if_none
std.py	bind_json_std
text.py	fullstr, is_binary, is_email_address, is_int, is_negative_int, is_palindrome, is_payment_card, is_percentage, is_positive_int, is_url, remove_decimal_zeros, remove_number_commas, replace
warnings.py	deprecated
xml.py	iterparse

algorithm.py

fibonacci

fibonacci(n=None)

Returns a generator with fibonacci series.

:param Optional[int] n: number iterations. must be None or an integer: 0 <= x <= sys.maxsize
:rtype: Generator[int]

luhn

luhn(value: str) -> bool

The Luhn algorithm or Luhn formula, also known as the "modulus 10" or "mod 10" algorithm,
named after its creator, IBM scientist Hans Peter Luhn,
is a simple checksum formula used to validate a variety of
identification numbers, such as credit card numbers, IMEI numbers, National Provider Identifier numbers

Based on: https://en.wikipedia.org/wiki/Luhn_algorithm

boolean.py

string2bool

string2bool(value, ignorecase=False)

Function to convert a string representation of
truth to True or False.

:param str value: value to convert.
:param bool ignorecase: Uppercase/lowercase letters of given "value" are ignored.

:raise: "ValueError" if "value" is anything else.
:rtype: bool

Examples:
    from pymince.boolean import string2bool

    string2bool("true") # --> True
    string2bool("false") # --> False

    string2bool("TRUE") # --> ValueError
    string2bool("TRUE", ignorecase=True) # --> True

    string2bool("FALSE") # --> ValueError
    string2bool("FALSE", ignorecase=True) # --> False

dates.py

irange

irange(start_date, stop_date=None, time_step=None)

Returns a generator that produces a sequence of datetime's from "start_date" (inclusive)
to "stop_date" (exclusive) by "time_step".

:param datetime.datetime start_date: Inclusive.
:param datetime.datetime stop_date: Exclusive. `utcnow` is used by default.
:param datetime.delta time_step: one-day `timedelta` is used by default.

 Examples:
    import datetime

    from pymince.dates import irange

    ini = datetime.datetime.fromisoformat("2022-10-31")
    end = datetime.datetime.fromisoformat("2022-11-02")
    day = datetime.timedelta(days=1)

    it = irange(ini, stop_date=end, time_step=day)

    next(it) # --> datetime.datetime(2022, 10, 31, 0, 0)
    next(it) # --> datetime.datetime(2022, 11, 1, 0, 0)
    next(it) # --> raise StopIteration

string2year

string2year(value, gte=None, lte=None, shift=None)

Function to convert a string year representation to integer year.

:param str value: Value to convert.
:param Optional[int] gte: if it is specified is required that: year >= gte
:param Optional[int] lte: if it is specified is required that: year <= lte
:param Optional[int] shift: use a two-digit year on shift

:raise: "ValueError" if "value" cannot be converted.
:rtype: int

Examples:
    from pymince.dates import string2year

    string2year("53", shift=None) # --> 2053
    string2year("53", shift=1953) # --> 1953
    string2year("52", shift=1953) # --> 2052
    string2year("54", shift=1953) # --> 1954

    string2year("1954") # --> 1954

    string2year("123") # --> ValueError
    string2year("1955", gte=1956) # --> ValueError
    string2year("1955", lte=1954) # --> ValueError

dictionary.py

Useful functions that use dictionaries

DigestGetter

DigestGetter(include_keys=None, exclude_keys=None)

Calculate a digest of a "jsonified" python dictionary.

:param include_keys: dictionary keys to exclude
:param exclude_keys: dictionary keys to include
:rtype: str

Examples:
    from pymince.dictionary import DigestGetter

    getter = DigestGetter(include_keys=("a",))
    getter({"a": 1, "b": 1}) # --> bb6cb5c68df4652941caf652a366f2d8
    getter({"a": 1}) # --> bb6cb5c68df4652941caf652a366f2d8

all_true_values

all_true_values(dictionary, keys)

Check if an dictionary has all specified keys and
key-related values as True.

:param dict dictionary:
:param keys: keys sequence
:rtype: bool

Examples:
from pymince.dictionary import all_true_values

all_true_values({"a": 1, "b": 2}, ("a", "b")) # --> True
all_true_values({"a": 1, "b": 0}, ("a", "b")) # --> False
all_true_values({"a": 1, "b": 0}, ("a",)) # --> True

find_leaf_value

find_leaf_value(key, dictionary)

Find leaf value in mapping.

:param str key:
:param dict dictionary:

Examples:
    from pymince.dictionary import find_leaf_value

    find_leaf_value('a', {}) # --> 'a'
    find_leaf_value('a', {'a': 'b', 'b': 'c'}) # --> 'c'
    find_leaf_value('a', {'a': 'a'}) # --> 'a'

from_objects

from_objects(iterable, key_getter, value_getter)

Create a new dictionary with elements generated from
the "key_getter" and "value_getter" callbacks applied to each element of the iterable.

:param Iterable[any] iterable:
:param Callable key_getter:
    Dictionary keys getter.
    It is called with each element of "iterable" passing it as an argument.
:param Callable value_getter:
    Dictionary values getter.
    It is called with each element of "iterable" passing it as an argument.

:raise: ValueError if any generated key is duplicate.
:rtype: dict

Examples:
    from pymince.dictionary import from_objects

    keygetter = operator.itemgetter(0)
    valgetter = operator.itemgetter(1, 2)

    values = iter([(1, "a", "b"), (2, "a", "b")])
    from_objects(values, keygetter, valgetter) # --> {1: ('a', 'b'), 2: ('a', 'b')}

frozendict

frozendict(*args, **kwargs)

Returns a "MappingProxyType" from a dictionary built according to given parameters.
Add immutability only on a first level.

Examples:
    from pymince.dictionary import frozendict

    my_dict = frozendict(a=1, b=2)
    my_dict["a"] # --> 1
    list(my_dict.items())  # --> [("a", 1), ("b", 2)]

file.py

decompress

decompress(src_path, dst_path)

Decompress given file in blocks using gzip.

:param str src_path: source file path
:param str dst_path: destination file(unzipped) path
:return: dst_path

 Examples:
    from pymince.file import decompress

    decompress("/foo/src.txt.gz", "/baz/dst.txt") # --> "/baz/dst.txt"

ensure_directory

ensure_directory(path, cleaning=False)

Make sure the given file path is an existing directory.
If it does not exist, a new directory will be created.

:param str path:
:param bool cleaning:
    If "cleaning" is True and a directory already exists,
    this directory and the files contained in it will be deleted.

    If "cleaning" is True and a file already exists,
    this file will be deleted.

is_empty_directory

is_empty_directory(path)

Function to check if the given path is an empty directory.

:param str path:
:rtype: bool

match_from_zip

match_from_zip(zip_file, pattern)

Make an iterator that returns file names in the zip file that
match the given pattern.
Uppercase/lowercase letters are ignored.

:param zip_file: ZipFile object or zip path.
:param pattern: "re.Pattern" to filter filename list
:return: Iterator with the filenames found

Examples:
    import pymince.file
    pymince.file.match_from_zip("archive.zip", "^file") # --> file1.log file2.txt
    pymince.file.match_from_zip(zipfile.ZipFile("archive.zip"), "^file") # --> file1.log file2.txt

replace_extension

replace_extension(filename, old_ext=None, new_ext=None)

Replace filename "old_ext" with "new_ext"

:param str filename:
:param Optional[str] old_ext:
:param Optional[str] new_ext:

Examples:
    from pymince.file import replace_extension

    # remove extensions
    replace_extension("/home/user/file.old") # --> "/home/user/file"
    replace_extension("/home/user/file.old", old_ext=".old") # --> "/home/user/file"
    replace_extension("/home/user/file.old", old_ext=".new") # --> "/home/user/file.old"

    # replace extensions
    replace_extension("/home/user/file.old", new_ext=".new") # --> "/home/user/file.new"
    replace_extension("/home/user/file.old", old_ext=".old", new_ext=".new") # --> "/home/user/file.new"
    replace_extension("/home/user/file.old", old_ext=".new", new_ext=".new") # --> "/home/user/file.old"

functional.py

classproperty

classproperty(method=None)

Decorator that converts a method with a single cls argument into a property
that can be accessed directly from the class.

Examples:
    from pymince.functional import classproperty

    class MyClass:
        __foo = "var"

        @classproperty
        def foo(cls):
            return cls.__foo

iterator.py

Functions that use iterators for efficient loops

all_distinct

all_distinct(iterable, key=None)

Check if all the elements of a key-based iterable are distinct.

:param iterable:
:param key: None or "Callable" to compare if iterable items.
:rtype: bool

Examples:
    from pymince.iterator import all_distinct

    all_distinct([1, 1]) # --> False
    all_distinct([1, 2]) # --> True

all_equal

all_equal(iterable, key=None)

Check if all the elements of a key-based iterable are equals.

:param iterable:
:param key: None or "Callable" to compare if iterable items.
:rtype: bool

Examples:
    from pymince.iterator import all_equal

    all_equal([1, 1]) # --> True
    all_equal([1, 2]) # --> False

all_equals

all_equals(*iterables, key=None)

Check if the iterables are equal.
If the "iterables" are empty, it returns True.

:param iterables:
:param key: None or "Callable" to compare if iterable items.
:rtype: bool

Examples:
    from pymince.iterator import all_equals

    all_equals() # --> True
    all_equals(range(1, 4), (1, 2, 3), {1, 2, 3}) # --> True
    all_equals((1, 2), (1, 2, 3)) # --> False

all_identical

all_identical(left, right)

Check that the items of `left` are the same objects
as those in `right`.

:param Iterable[Any] left:
:param Iterable[Any] right:
:rtype: bool

Examples:
    from pymince.iterator import all_identical

    a, b = object(), object()
    all_identical([a, b, a], [a, b, a]) # --> True
    all_identical([a, b, [a]], [a, b, [a]])  # --> False *new list object, while "equal" is not "identical"*

consume

consume(iterator, n=None)

Advance *iterator* by *n* steps. If *n* is ``None``, consume it
entirely.

Examples:
    from pymince.iterator import consume
    it = iter([1, 2])
    consume(it)
    next(it) # --> StopIteration

contains

contains(iterable, obj)

Check if the object is contained in given iterable.

:param Any obj:
:param iterable:
:rtype: bool

grouper

grouper(iterable, size)

Make an iterator that returns each element being iterable
with "size" as the maximum number of elements.

:param iterable:
:param int size: maximum size of element groups.

Examples:
    from pymince.iterator import grouper

    groups = grouper([1, 2, 3, 4, 5], 2)
    list(list(g) for g in groups) # --> [[1, 2], [3, 4], [5]]

has_only_one

has_only_one(iterable)

Check if given iterable has only one element.

:param iterable:
:rtype: bool

Examples:
    from pymince.iterator import has_only_one

    has_only_one([1]) # --> True
    has_only_one([1, 2]) # --> False
    has_only_one([]) # --> False

ibool

ibool(iterable)

Iterator class supporting __bool__.

Examples:
    from pymince.iterator import ibool

    it = ibool((1, 2, 3))
    bool(it) # --> True
    list(it) # --> [1, 2, 3]

in_all

in_all(obj, iterables)

Check if the object is contained in all the given iterables.
If the "iterables" are empty, return True.

:param Any obj:
:param iterables: iterable of iterables
:rtype: bool

Examples:
    from pymince.iterator import in_all

    in_all("a", (("a", "b"), "bcd")) # --> False
    in_all("a", (("a", "b"), "abc")) # --> True
    in_all("a", ()) # --> True

in_any

in_any(obj, iterables)

Check if the object is contained in any of the given iterables.

:param Any obj:
:param iterables: iterable of iterables
:rtype: bool

Examples:
    from pymince.iterator import in_any

    in_any("a", (("a", "b"), "bcd")) # --> True
    in_any("a", (("b", "b"), "def")) # --> False
    in_any("a", ()) # --> False

pad_end

pad_end(iterable, length, fill_value=None)

The function adds "fill_value" at the finishing of the iterable,
until it reaches the specified length.
If the value of the "length" param is less than the length of
the given "iterable", no filling is done.

:param iterable:
:param int length: A number specifying the desired length of the resulting iterable.
:param Any fill_value: Any value to fill the given iterable.
:rtype: Generator

 Examples:
    from pymince.iterator import pad_end

    pad_end(("a", "b"), 3, fill_value="1") # --> "a" "b" "1"
    pad_end(("a", "b"), 3) # --> "a" "b" None
    pad_end(("a", "b", "c"), 3) # --> "a" "b" "c"

pad_start

pad_start(iterable, length, fill_value=None)

The function adds "fill_value" at the beginning of the iterable,
until it reaches the specified length.
If the value of the "length" param is less than the length of
the given "iterable", no filling is done.

:param iterable:
:param int length: A number specifying the desired length of the resulting iterable.
:param Any fill_value: Any value to fill the given iterable.
:rtype: Generator

 Examples:
    from pymince.iterator import pad_start

    pad_start(("a", "b"), 3, fill_value="1") # --> "1" "a" "b"
    pad_start(("a", "b"), 3) # --> None "a" "b"
    pad_start(("a", "b", "c"), 3) # --> "a" "b" "c"

replacer

replacer(iterable, matcher, new_value, count=-1)

Make an iterator that returns all occurrences of the old "iterable"
replaced by "new_value".

:param iterable:
:param matcher: Callable to find occurrences. It is an occurrence if the matcher returns True.
:param new_value: Any value to replace found occurrences.
:param int count:
    Maximum number of occurrences to replace.
    -1 (the default value) means replace all occurrences.

Examples:
    from pymince.iterator import replacer

    replacer([1,2,3,1,2,3], lambda n: n == 1, None) # --> None 2 3 None 2 3
    replacer([1,2,3,1,2,3], lambda n: n == 1, None, count=1) # --> None 2 3 1 2 3

splitter

splitter(iterable, sep, key=None, maxsplit=-1)

Split iterable into groups of iterators according
to given delimiter.

:param iterable:
:param sep: The delimiter to split the iterable.
:param key
    A function to compare the equality of each element with the given delimiter.
    If the key function is not specified or is None, the element itself is used for compare.

:param maxsplit:
    Maximum number of splits to do.
    -1 (the default value) means no limit.

:return: Generator with consecutive groups from "iterable" without the delimiter element.

Examples:
    from pymince.iterator import splitter

    data = ["a", "b", "c", "d", "b", "e"]

    undefined_split = splitter(data, "b")
    one_split = splitter(data, "b", maxsplit=1)
    list(list(s) for s in undefined_split) # --> [["a"], ["c", "d"], ["e"]]
    list(list(s) for s in one_split) # --> [["a"], ["c", "d", "b", "e"]]

uniquer

uniquer(iterable, key=None)

Make an iterator that returns each element from iterable only once
respecting the input order.

Examples:
    from pymince.iterator import uniquer

    uniquer([1, 2, 3, 2]) # --> 1 2 3

uniques

uniques(iterable, key=None)

Check if all the elements of a key-based iterable are unique.

:param iterable:
:param key: None or "Callable" to compare if iterable items.
:rtype: bool

Examples:
    from pymince.iterator import uniques

    uniques([1,2]) # --> True
    uniques([1,1]) # --> False

json.py

dump_into

dump_into(filename, payload, indent=None)

Dump JSON to a file using "utf-8" encoding.

Examples:
    from pymince.json import dump_into

    dump_into("foo.json", {"key": "value"})

dump_into_zip

dump_into_zip(zip_path, arcname, payload, indent=None)

Dump JSON into the zip archive under the name arcname.

Examples:
    from pymince.json import dump_into_zip

    dump_into_zip("archive.zip", "foo.json", {"key": "value"})

load_from

load_from(filename)

Load JSON from a file using "utf-8" encoding.

Examples:
    from pymince.json import load_from

    dictionary = load_from("foo.json")

load_from_zip

load_from_zip(zip_path, arcname)

Load JSON from a file named "arcname" inside a zip archive.

Examples:
    from pymince.json import load_from_zip

    dictionary = load_from_zip("archive.zip", "foo.json")

logging.py

StructuredFormatter

StructuredFormatter(fmt=None, datefmt=None, style='%', validate=True)

Implementation of JSON structured logging that works
for most handlers.

Examples:
    import logging
    import sys
    from pymince.logging import StructuredFormatter

    # Config
    logger = logging.getLogger()
    logger.setLevel(logging.DEBUG)
    formatter = StructuredFormatter('%(message)s')
    handler = logging.StreamHandler(sys.stdout)
    handler.setLevel(logging.DEBUG)
    handler.setFormatter(formatter)
    logger.addHandler(handler)

    # Usage
    logger.debug('', {"string": "value1", "number": 1})
    logger.debug('', {"string": "value2", "number": 2})

    >>Output<<
    {"timestamp":"2022-06-17 18:37:48,789","level":"DEBUG","payload":{"string":"value1","number":1}}
    {"timestamp":"2022-06-17 18:37:48,789","level":"DEBUG","payload":{"string":"value2","number":2}}

timed_block

timed_block(name, logger=None)

Logger the duration of the handled context.

Examples:
    import logging
    from pymince.logging import timed_block

    logging.basicConfig(level=logging.DEBUG)
    with timed_block("sleeping"):
        time.sleep(1)

    >>Output<<
    INFO:root:Generating [sleeping]
    DEBUG:root:Finished [sleeping in 1.002 ms.]

retry.py

retry_if_errors

retry_if_errors(*exceptions, delay=0, tries=1)

Decorator that retries to call the wrapped function
if any of given exceptions are thrown.

:param exceptions: Lists of exceptions that trigger a retry attempt.
:param int delay: seconds delay between attempts. default: 0.
:param int tries: number of attempts. default: 1

Examples:
@retry_if_errors(ValueError, TypeError, delay=0, tries=1)
def foo():
    return 1

retry_if_none

retry_if_none(delay=0, tries=1)

Decorator that retries to call the wrapped function
if it returns None.

:param int delay: seconds delay between attempts. default: 0.
:param int tries: number of attempts. default: 1

Examples:
    @retry_if_none(delay=0, tries=1)
    def foo():
        return 1

std.py

bind_json_std

bind_json_std(encoding='utf-8')

Decorator to call "function" passing the json read from
"stdin" in the keyword parameter "data" and dump the json that the callback returns
to "stdout".

Examples:
from pymince.std import bind_json_std

@bind_json_std()
def foo(data=None):
    print("Processing data from sys.stdin", data)

    result = data and {**data, "new": "value"}

    print("Result to write in sys.stdout", result)
    return result

text.py

Useful functions for working with strings.

fullstr

fullstr()

Custom string inheriting from "str" which adds
the following methods:

- is_url(self, schemes=None, hostnames=None)
- is_int(self)
- is_positive_int(self)
- is_negative_int(self)
- is_payment_card(self)
- is_binary(self)
- is_percentage(self)
- is_palindrome(self)
- is_email_address(self)

is_binary

is_binary(text)

Check if the string is binary or not.

is_email_address

is_email_address(text)

Check if the string is an email address.

This solution does a very simple check. It only validates that the string contains an at sign (@)
that is preceded and followed by one or more non whitespace characters.

is_int

is_int(text)

Check if the string is the representation of
a integer number.

True:
 "10",   "10.",   "10.0",
"+10",  "+10.",  "+10.0",
"-10",  "-10.",  "-10.0"

is_negative_int

is_negative_int(text)

Check if the string is the representation of
negative integer number.

True:
"-10",  "-10.",  "-10.0"

is_palindrome

is_palindrome(text)

Check if the string is palindrome or not.
A string is said to be palindrome if the reverse of the string is the same as string

is_payment_card

is_payment_card(text)

Check if the string is a valid payment
card number.

https://en.wikipedia.org/wiki/Payment_card_number#Issuer_identification_number_(IIN)

is_percentage

is_percentage(text)

Check if the string is a valid percentage

True: "100%", "100 %", "100 %", 100.0 %",

is_positive_int

is_positive_int(text)

Check if the string is the representation of
positive integer number.

True:
 "10",   "10.",   "10.0",
"+10",  "+10.",  "+10.0",

is_url

is_url(text, schemes=None, hostnames=None)

Check if the string is a URL according to the
given schemes and host-names.

:param str text:
:param Optional[Container[str]] schemes: ("http", "https")
:param Optional[Container[str]] hostnames: ("www.python.org", "github.com", "localhost")
:rtype: bool

Examples:
    from pymince.text import is_url

    # True
    is_url("https://github.com/")
    is_url("https://github.com/", hostnames=("github.com",))
    is_url("https://github.com/", hostnames=("github.com",), schemes=("https",))

    # False
    is_url("https://github.com/", schemes=("http",))
    is_url("https://github.com/", hostnames=("www.python.org", "localhost"))

remove_decimal_zeros

remove_decimal_zeros(value, decimal_sep='.', min_decimals=None)

Removes non-significant decimal zeros from a formatted text number.

Examples:
    from pymince.text import remove_decimal_zeros

    remove_decimal_zeros("2.000100", ".") # --> "2.0001"
    remove_decimal_zeros("2.000000", ".") # --> "2"
    remove_decimal_zeros("2.000000", ".", min_decimals=2) # --> "2.00"

remove_number_commas

remove_number_commas(string)

Removes commas from a formatted text number having commas
as group separator.

:param str string:
:rtype str

Examples:
    from pymince.text import remove_number_commas
    remove_number_commas('1,234,567.8') # --> '1234567.8'

replace

replace(value, old_values, new_value, count=-1)

Replace matching values ​​in the given string with new_value.

:param str value:
:param old_values: iterable of values ​​to replace.
:param str new_value: replacement value.
:param int count:
    Maximum number of occurrences to replace.
    -1 (the default value) means replace all occurrences.
:rtype: str

Examples:
    from pymince.text import replace

    replace("No, woman, no cry", [","], ";") # --> "No; woman; no cry"
    replace("No, woman, no cry", [","], ";", count=1) # --> "No; woman, no cry"

warnings.py

deprecated

deprecated(fn)

This is a decorator which can be used to mark functions
as deprecated. It will result in a warning being emitted
when the function is used.
http://code.activestate.com/recipes/391367-deprecated/?in=lang-python

Examples:
    from pymince.warnings import deprecated

    @deprecated
    def check_function():
        pass

    class SomeClass:
        @deprecated
        def check_method(self):
            pass

    @deprecated
    class CheckClass:
        pass

    >> check_function() # DeprecationWarning  --> 'Deprecated "check_function".'
    >> SomeClass().check_method() #  DeprecationWarning --> 'Deprecated "check_method".'
    >> CheckClass() # DeprecationWarning  --> 'Deprecated "CheckClass".'

xml.py

iterparse

iterparse(filename)

Incrementally parse XML document into ElementTree.

This function is based on: https://github.com/python/cpython/issues/93618

'Fix misleading hint for original ElementTree.iterparse.'
'''
The code below deletes a root child once it is completed, then processes and removes
it from the memory (if nothing more references to it ofc).
This allows to process 7GB XML with with a memory usage up to 10MB (in case of great number of root children).
'''

:param str filename: XML filename
:rtype: Generator

 Examples:
    from pymince.xml import iterparse

    for event, obj in iterparse("countries.xml")
        if event == 'start'
            print(obj, obj.tag, obj.attrib, obj.text)

    >>Output<<
    <Element 'country' at 0x0000018ADF9D0CC0> country {'code': 'as', 'iso': '16'} American Samoa
    <Element 'country' at 0x0000018ADF9D0C70> country {'code': 'ad', 'iso': '20'} Andorra

Upgrade README.md

Upgrade README.md Usage section according to current pymince code.

(env) python upgrade_readme_usage.py