notalib 2.4.0

A collection of utility functions & classes

notalib

Collection of small Python utility functions and classes. Each one was created because I needed it and it didn't exist or I didn't like the existing implementations. 100% of code is used in real-world projects.

(And one day, the documentation is going to be actually good. In the meanwhile, don't hesitate to ask if something's not clear.)

Install

pip install notalib

Or with poetry:

poetry add notalib

Compatibility promise

Version numbers follow the semver rules.

• Minor releases are backwards-compatible. For example, an upgrade from 1.2 to 1.4 should be safe.
• Major releases are not backwards-compatible. For example, an upgrade from 1.4 to 2.0 is unsafe — read the release notes to see what's changed.

Maintenance & bugfixes

While I try to fix bugs, add new features, and review any PRs when I have time, there're no promises and no set timeframes, even if a bug is critical. That's a project I do in my free time, free of charge.

If that's not enough for you or you have an urgent request, there are paid maintenance options (bugfixing, features, expedite PR review, 24h security responses). Contact me for prices: [e-mail]

Also feel free to just send me money:

• MasterCard: 5559 4925 7484 0297
• PayPal: paypal.me/thisism1kc

Donations are always appreciated, even if you send 10$.

Constants included

• notalib.utf.BOM: contains string b'\xEF\xBB\xBF' (UTF-8 little endian byte order mark).

Utils included

notalib.array.as_chunks :fire:

Iterates over your array in chunks of at most N elements.

from notalib.array import as_chunks

arr = [1,2,3,4,5]
for chunk in as_chunks(arr, 2):
    print(chunk)
# [1,2]
# [3,4]
# [5]

notalib.array.ensure_iterable :fire:

Keeps iterable things like lists intact, turns single values into single-element lists. Useful for functions that can accept both.

ensure_iterable([1,2,3])  # --> [1,2,3]
ensure_iterable((1,2,3))  # --> (1,2,3)
ensure_iterable(1)        # --> [1]
ensure_iterable('smth')   # --> ['smth']

def my_function(one_or_multiple_args):
    for arg in ensure_iterable(one_or_multiple_args):
        ...

my_function(['log', 'smog'])
my_function('dog')

notalib.array.batched

Batch data from the iterable into tuples of length n.

from notalib.array import batched


def generate_numbers():
    for i in range(10):
        yield i


batches = list(batched(generate_numbers(), 5))     # --> [(0, 1, 2, 3, 4), (5, 6, 7, 8, 9)]
batches = list(batched("Hello", 2))     # --> [('H', 'e'), ('l', 'l'), ('o',)]

notalib.combinator.Combinator :fire:

notalib.date.parse_month

notalib.date.parse_date

notalib.date.normalize_date :fire:

Re-formats a date, parsing it as any of the input_formats and outputting it as output_format.

This function uses Arrow date formats. See Arrow docs for details.

Args:
	s: The source date in one of the input_formats to be converted to target format.
	input_formats: Source date representation formats.
	output_format: The format in which the date will be output.
	allow_empty: if true, `None` input will produce `None` output, otherwise a ValueError will be thrown.

Example:
	>>> normalize_date('12.07.2023', ('D.M.YYYY', 'DD.MM.YYYY'), 'YYYY-MM-DD', False)
	'2023-07-12'

Returns:
	Converted date string from any of the input formats to the specified output format.

notalib.date.get_week_number

Removed in 2.0.0. Use get_week instead. If you want the "old" week numbering, use get_week with WeekNumbering.MATCH_YEAR and add 1 to week number.

notalib.date.get_week

Returns named tuple with week number for the given date. Accepts Python dates and Arrow timestamps.

Optional argument mode tells what to do if the week started in previous year:

• WeekNumbering.NORMAL (default): consider it the last week of the previous year
• WeekNumbering.MATCH_YEAR: consider it 0-th week of current year

from notalib.date import get_week, WeekNumbering
from datetime import date

date1, date2 = date(2022, 12, 31), date(2023, 1, 1)
get_week(date1, WeekNumbering.NORMAL)
# Week(week=52, year=2022)

get_week(date1, WeekNumbering.MATCH_YEAR)
# Week(week=52, year=2022)

get_week(date2, WeekNumbering.NORMAL)
# Week(week=52, year=2022)

get_week(date2, WeekNumbering.MATCH_YEAR)
# Week(week=0, year=2023)

notalib.dict.deep_merge

:warning: Experimental API. Subject to change. Don't use in production. You've been warned.

Merges two dicts.

Modifies input. Use copy.deepcopy to create a deep copy of the original dictionary if you need it.

Accepts three arguments:

• original dict (also target)
• second dict
• overwrite=True if you want to overwrite matching paths, overwrite=False to raise an exception on path conflicts (default)

notalib.dict.find_field

notalib.dict.find_value

notalib.dict.normalize_dict :fire:

notalib.dict.filter_dict

Filters a dictionary, removing any keys except for the ones you choose.

from notalib.dict import filter_dict

src = {
	'Some': "BODY",
	'once': "told me",
	'the world': "is gonna roll me",
}
filter_dict(src, ["Some", "once"])
# {'Some': 'BODY', 'once': 'told me'}
filter_dict(src, [])
# {}

notalib.format.format_long_list

notalib.timedelta.convert_timedelta

:warning: Experimental API. Subject to change. Don't use in production. You've been warned.

Converts standard timedelta object to specified formats.

Allowed formats: 's', 'ms'.

from notalib.timedelta import convert_timedelta
from datetime import timedelta

td = timedelta(seconds=1, milliseconds=23)
convert_timedelta(td, 's')
# 1.023
convert_timedelta(td, 'ms')
# 1023

notalib.hypertext.strip_tags :fire:

notalib.hypertext.TablePrinter :fire:

Prints an HTML table, row by row, from the given data, using attrs or dictionary keys as columns.

Two ways to use it:

• Call header() / entry() / footer() manually

from notalib.hypertext import TablePrinter
t = TablePrinter(['a', 'b'])
t.header()
# '<table><thead><tr><th>a</th><th>b</th></tr></thead><tbody>'
t.entry({'a': 1, 'b': 2})
# '<tr><td>1</td><td>2</td></tr>\n'
t.entry({'a': 11, 'b': 22})
# '<tr><td>11</td><td>22</td></tr>\n'
t.footer()
# '</tbody></table>'

• Pass an iterable to iterator_over()

from notalib.hypertext import TablePrinter
t = TablePrinter(['a', 'b'])
list(t.iterator_over([ {'a': 11, 'b': 22} ]))
# ['<table><thead><tr><th>a</th><th>b</th></tr></thead><tbody>',
#  '<tr><td>11</td><td>22</td></tr>\n',
#  '</tbody></table>']

notalib.polosa.polosa :fire: :fire: :fire: :fire: :fire:

18023/2000000   294.8/sec   Processing transaction ID#84378473 (2020-01-04)

The CLI progress indicator you've always dreamt of: shows current and total if available, measures current speed, can show your comments for each element, makes sure not to slow down your terminal with frequent updates. See this short demo.

Cheat sheet

## Basic usage
with polosa() as p:
    p.tick()
# 467344   201.2/sec

## Specify total number of elements:
with polosa(total=1337) as p:
# 26/1337   1.2/sec

## Print something useful about every element:
p.tick(caption=my_order.time_created)
# 1723910/2000000   319231.2/sec   2020-01-01 15:37:00

notalib.range.Range

notalib.time.Timing :fire:

Measures time spent on executing your code. Killer feature: it can be used as a reusable context.

timing = Timing()
...
with timing:
    do_something()
# That's it, do something with the measurement
log(f'Operation took {timing.result} sec')

If you just want to print measurements into console, there's a shorthand:

timing = Timing(auto_print=True)
...
with timing:
    do_something()

notalib.trendsetter.Trendsetter :fire:

notalib.git.get_current_commit

:warning: Experimental API. Subject to change. Don't use in production. You've been warned.

Returns short description and hash of last commit of current branch. If function is called outside git repo or there are no commits in the history, None will be returned.

from notalib.git import get_current_commit

commit = get_current_commit()
# Commit(hash='db0e5c1de83f233abef823fd92490727f4ee9d50', short_description='Add timedelta module with convert_timedelta function')

notalib.git.get_last_tag

:warning: Experimental API. Subject to change. Don't use in production. You've been warned.

Returns last tag label and hash. If function is called outside git repo or there are no tags in the history, None will be returned.

from notalib.git import get_last_tag

tag = get_last_tag()
# Tag(hash='c4b6e06f57ab4773e2881d286804d4e3141b5195', label='v1.4.0')

notalib.file_iterator.file_iterator

Iterates over byte buffer and yields chunks of specified size.

with open("<file_path>", mode="rb") as file:
    for chunk in file_iterator(file):
        ...

Tools for Pandas

notalib.pandas.pandasplus.row_to_dict

notalib.pandas.pandasplus.replace_null_objects

Replaces all types of null values in a DataFrame with the given value.

df = pd.DataFrame({'A': [pd.NA, pd.NaT, 'SomeVal', None]})
new_df = replace_null_objects(df, "Hello, notalib!")
new_df
#                  A
# 0  Hello, notalib!
# 1  Hello, notalib!
# 2          SomeVal
# 3  Hello, notalib!

Tools for Django

notalib.django.auth.StaticBackend

notalib.django.auth.SettingsBackend

notalib.django.xauth

Endpoints for easier authentication in APIs. Requires Django REST framework.

Provides endpoints:

• GET /xauth/check — returns code 200 if client is authenticated (or global permissions are set to AllowAny), 403 if not
• POST /xauth/auth-post — authenticates a client; accepts two POST parameters username and password; returns code 200 on success and 403 on failure
• POST /xauth/logout — de-authenticates a client

How to use:

1. Make sure Django REST framework is installed.
2. Add 'notalib.django_xauth' to INSTALLED_APPS.
3. Run manage.py migrate django_xauth (doesn't actually change your DB).
4. Add something like this to your urls.py: path('xauth/', include('notalib.django_xauth.urls')),

notalib.django.colorlog.ColorFormatter

notalib.django.filterset :fire:

notalib.django.formplus.MonthField

notalib.django.formplus.ChoiceWithDefault

notalib.django.formplus.IntegerArrayField

notalib.django.formplus.StringArrayField

notalib.django.formplus.MonthArrayField

notalib.django.http.HttpResponseSeeOther

Spec-compliant HTTP 303 See Other redirect (Django only provides deprecated 301 and 302).

notalib.django.http.HttpResponseTemporaryRedirect

Spec-compliant HTTP 307 Temporary Redirect (Django only provides deprecated 301 and 302).

notalib.django.request_time_middleware.RequestTimeLoggingMiddleware

notalib.django.stream.stream_json

Stream all elements of iterable object as JSON array using the StreamingHttpResponse class. Unlike DRF's Response class, it can handle arrays of any size.

class SomeViewSet(...):
    ...

    def list(self, request, *args, **kwargs):
        ...
        return stream_json(data)

notalib.django.bytes_stream.get_stream_bytes_response

Stream bytes IO part by the RANGE header value or all buffer content.

class SomeView(...):
    def get(self, request, *args, **kwargs):
        with open("<file_path>", mode="rb") as file:
            ...
            return get_stream_bytes_response(file, request, content_type="<file_content_type>")

Django/Clickhouse

Deprecated since 2.2.0.

Click to expand

Required packages: clickhouse-sqlalchemy

Required two django.settings variables:

• CLICKHOUSE_URL — database URL
• CLICKHOUSE_PROFILE — dump all queries and their timing to console, true/false

notalib.django.clickhouse.base.get_connection

notalib.django.clickhouse.base.get_database_name

notalib.django.clickhouse.base.Query

A wrapper for SQLAlchemy's select with some useful postprocessing options.

• execute — no postprocessing
• execute_val — returns single value
• execute_list — returns single column as list
• execute_kv — returns dict, first column becomes keys, second column becomes values
• execute_na — returns number of affected rows

Usage example:

q = Query(
    select([ SomeTable.c.notalib ])
)
q.execute_list()
# ["Example", "OOOOO", "my", "defence", ...]

notalib.django.clickhouse.mutations.get_mutations_in_progress_count

Returns the number of mutations in progress for the specified table.

get_mutations_in_progress_count("SOME_DATABASE", "SOME_TABLE_IN_DATABASE")
# 5

notalib.django.clickhouse.wait.wait_result :fire:

Waits until all mutations for the given table are complete.

# blah blah blah, ALTER TABLE ... UPDATE ...
wait_result("SOME_DATABASE", "SOME_TABLE_IN_DATABASE")
# UPDATE complete, continue

Tools for Tablib

:warning: Experimental API. Subject to change. Don't use in production. You've been warned.

Required packages: tablib

notalib.tablib.shortcuts.load_dataset

:warning: Experimental API. Subject to change. Don't use in production. You've been warned.

Allows to simplify the loading of datasets, even custom ones.

from notalib.tablib.shortcuts import load_dataset

with open("report.xlsx", mode='rb') as file:
    ds = load_dataset(file)

### Or you can use custom Dataset class and format

from tablib import Dataset


class MyDataset(Dataset):
    pass


with open("report.csv", mode='rb') as file:
    ds = load_dataset(file, 'csv', MyDataset)

notalib.tablib.dataset.ExtendedDataset

:warning: Experimental API. Subject to change. Don't use in production. You've been warned.

Extended tablib.Dataset class, which adds useful data processing methods.

notalib.tablib.dataset.ExtendedDataset.drop_duplicates

Removes all duplicate rows from the ExtendedDataset object while maintaining the original order.

notalib.tablib.dataset.ExtendedDataset.drop_empty

Removes rows with empty data in specified columns.

notalib.tablib.dataset.ExtendedDataset.drop_empty_rows

Removes rows in which all values are empty.

notalib.tablib.dataset.ExtendedDataset.apply_to_column

Applies the function to the values in the specified column.

notalib.tablib.dataset.ExtendedDataset.replace_empty_objects

Replaces empty values with a new one.

notalib.tablib.dataset.ExtendedDataset.set_used_columns

Returns a new dataset based on the specified header labels.

notalib.tablib.dataset.ExtendedDataset.get_headers_map

Returns a list of Boolean objects based on a given set of header labels.

notalib.tablib.dataset.ExtendedDataset.get_header_index

Calculates the index of the header by its label.

notalib.tablib.dataset.ExtendedDataset.groupby

Sets tags to rows and returns list of groups for filtering.

notalib.tablib.dataset.ExtendedDataset.rename_headers

Renames header labels.