import argparse
def hello(args):
print('Hello, {0}!'.format(args.name))
def goodbye(args):
print('Goodbye, {0}!'.format(args.name))
parser = argparse.ArgumentParser()
subparsers = parser.add_subparsers()
hello_parser = subparsers.add_parser('hello')
hello_parser.add_argument('name') # add the name argument
hello_parser.set_defaults(func=hello) # set the default function to hello
goodbye_parser = subparsers.add_parser('goodbye')
goodbye_parser.add_argument('name')
goodbye_parser.set_defaults(func=goodbye)
if __name__ == '__main__':
args = parser.parse_args()
args.func(args) # call the default function
$ python argparse_test.py hello Johnny
Hello, Johnny!
$ python argparse_test.py hello --help
usage: argparse_test.py hello [-h] name
positional arguments:
name
optional arguments:
-h, --help show this help message and exit
"""
Usage:
docopt_test.py hello <name>
docopt_test.py goodbye <name>
docopt_test.py (-h | --help)
"""
from docopt import docopt
def hello(name):
print('Hello, {0}!'.format(name))
def goodbye(name):
print('Goodbye, {0}'.format(name))
if __name__ == '__main__':
arguments = docopt(__doc__)
# if an argument called hello was passed, execute the hello logic.
if arguments['hello']:
hello(arguments['<name>'])
elif arguments['goodbye']:
goodbye(arguments['<name>'])
$ python docopt_test.py hello Johnny
Hello, Johnny!
$ python docopt_test.py hello --help
Greeter.
Usage:
docopt_test.py hello <name>
docopt_test.py goodbye <name>
docopt_test.py (-h | --help)
Options:
-h --help Show this screen.
import click
@click.group()
def greet():
pass
@greet.command()
@click.argument('name') # add the name argument
def hello(name):
print(f'Hello, {name}!')
@greet.command()
@click.argument('name')
def goodbye(**kwargs):
print(f'Goodbye, {kwargs["name"]}!')
if __name__ == '__main__':
greet()
$ python click_test.py hello Johnny
Hello, Johnny!
$ python click_test.py hello --help
Usage: click_test.py hello [OPTIONS] NAME
Options:
--help Show this message and exit.
import fire
def hello(name):
return f"Hello, {name}!"
if __name__ == '__main__':
fire.Fire(hello)
$ python fire_test.py Johnny
Hello, Johnny!
$ python fire_test.py --help
INFO: Showing help with the command 'fire_test.py -- --help'.
NAME
fire_test.py
SYNOPSIS
fire_test.py NAME
POSITIONAL ARGUMENTS
NAME
NOTES
You can also use flags syntax for POSITIONAL ARGUMENTS
pick
pick
Command line menu mini framework
Installation:
pip install pick
Example:
from pick import pick
title = 'Please choose your favorite programming language: '
options = ['Java', 'JavaScript', 'Python', 'PHP', 'C++', 'Erlang', 'Haskell']
option, index = pick(options, title)
print(option)
produces this:
tqdm
Command line progress bar framework
🪄 Code:
from tqdm import tqdm
l = []
for i in tqdm(range(10000)):
l.append(i ** i)
Simple cross-platform colored terminal text in Python
Makes ANSI escape character sequences (for producing colored terminal text and cursor positioning) work under MS Windows.
Colorama also provides some shortcuts to help generate ANSI sequences but works fine in conjunction with any other ANSI sequence generation library, such as the venerable Termcolor (https://pypi.org/project/termcolor/) or the fabulous Blessings (https://pypi.org/project/blessings/).
Possible color formattings:
🪄 Code:
from colorama import Fore, Back, Style
print(Fore.YELLOW + Back.BLUE + 'some yellow text')
print(Back.GREEN + 'and with a green background')
print("Test..")
print(Back.RED + Style.DIM + 'and in dim text') # Check in console...
print(Style.RESET_ALL)
print('back to normal now')
📟 Output:
[33m[44msome yellow text
[42mand with a green background
Test..
[41m[2mand in dim text
[0m
back to normal now
Yaspin
Yet Another Terminal Spinner for Python
import time
from random import randint
from yaspin import yaspin
with yaspin(text="Loading", color="yellow") as spinner:
time.sleep(2) # time consuming code
success = randint(0, 1)
if success:
spinner.ok("✅ ")
else:
spinner.fail("💥 ")
delta = tomorrow - last_week
print(f"In hours: {delta.hours}")
print(delta.in_words(locale='en'))
print(delta.in_words(locale='ru')) # <-- Only "ru" at the moment, no "ua" :(
📟 Output:
In hours: 23
1 week 23 hours 59 minutes 59 seconds
1 неделя 23 часа 59 минут 59 секунд
Loguru
A library which aims to bring enjoyable logging in Python.
🪄 Code:
from loguru import logger
logger.debug("That's it, beautiful and simple logging!")
import sys
# How to add a handler? How to set up logs formatting? How to filter messages? How to set level?
# One answer: the add() function.
logger.add(sys.stderr, format="{time} {level} {message}", filter="my_module", level="INFO")
# Pretty formatting
logger.add(sys.stdout, colorize=True, format="<green>{time}</green> <level>{message}</level>")
logger.debug("Check it now!")
📟 Output:
2019-09-20 13:09:10.415 | DEBUG | __main__:<module>:10 - Check it now!
[32m2019-09-20T13:09:10.415490+0000[0m [34m[1mCheck it now![0m
The code
logger.add("output.log", backtrace=True, diagnose=True) # Set 'False' to not leak sensitive data in prod
def func(a, b):
return a / b
def nested(c):
try:
func(5, c)
except ZeroDivisionError:
logger.exception("What?!")
nested(0)
will result in the following traceback debug log message:
2018-07-17 01:38:43.975 | ERROR | __main__:nested:10 - What?!
Traceback (most recent call last):
File "test.py", line 12, in <module>
nested(0)
└ <function nested at 0x7f5c755322f0>
> File "test.py", line 8, in nested
func(5, c)
│ └ 0
└ <function func at 0x7f5c79fc2e18>
File "test.py", line 4, in func
return a / b
│ └ 0
└ 5
ZeroDivisionError: division by zero
ConfigObj
Python 3+ compatible port of the configobj library.
debug = True
version = 0.1
services = ui, web, db
[logging]
log_level = INFO
log_file = /tmp/example.log
and use it like this:
from configobj import ConfigObj
config = ConfigObj("config.ini")
print(config['version']) # 0.1
print(config['services']) # ["ui", "web", "db"]
with open(config['logging']['log_file'] as f:
f.write(log_msg)
ConfigObj is a simple but powerful config file reader and writer: an ini file round tripper. Its main feature is that it is very easy to use, with a straightforward programmer’s interface and a simple syntax for config files. It has lots of other features though :
Nested sections (subsections), to any level
List values
Multiple line values
String interpolation (substitution)
Validation
Install as usual:
pip install configobj
Reading config
# As example let's read ini from "virtual" file:
import io
ini_contents = '''
debug = True
version = 0.1
services = ui, web, db, logging, web services
[logging]
log_level = INFO
log_file = /tmp/example.log
'''
f = io.StringIO(ini_contents) # File-like object
This powerful feature allows to validate provided ini file before parsing and using it.
Validation is done with the help of Validator object and configspec (which resembles your config file, with a check for every member). Basic checks:
boolean values (True and False)
integers (including minimum and maximum values)
floats (including min and max)
strings (including min and max length)
IP addresses (v4 only)
Example of configspec:
port = integer(0, 100)
user = string(max=25)
mode = option('quiet', 'loud', 'silent')
mode2 = option('quiet', 'loud', 'silent', default='loud')
nick = string(default=None)
Profiling
The profiling package is an interactive continuous Python profiler. It is inspired from Unity 3D profiler. This package provides these features:
> pip install profiling
Profiling statistics keep the frame stack.
An interactive TUI profiling statistics viewer.
Provides both of statistical and deterministic profiling.
Utilities for remote profiling.
Thread or greenlet aware CPU timer.
Supports Python 2.7, 3.3, 3.4 and 3.5.
Currently supports only Linux.
> profiling farm_unicorn.py
Requests
Warning: Recreational use of other HTTP libraries may result in dangerous side-effects, including: security vulnerabilities, verbose code, reinventing the wheel, constantly reading documentation, depression, headaches, or even death.
import requests
endpoint = 'https://catfact.ninja/facts?limit=5'
r = requests.get(endpoint)
print(r.status_code)
#print(r.json())
facts = r.json()['data']
for f in facts:
print(f"* {f['fact']}")
📟 Output:
200
* Unlike dogs, cats do not have a sweet tooth. Scientists believe this is due to a mutation in a key taste receptor.
* When a cat chases its prey, it keeps its head level. Dogs and humans bob their heads up and down.
* The technical term for a cat’s hairball is a “bezoar.”
* A group of cats is called a “clowder.”
* A cat can’t climb head first down a tree because every claw on a cat’s paw points the same way. To get down from a tree, a cat must back down.
'Some common houseplants poisonous to cats include: English Ivy, iris, mistletoe, philodendron, and yew.'
JSON
JSON is a lightweight data-interchange format. It is easy for humans to read and write. It is easy for machines to parse and generate. It is based on a subset of the JavaScript.
JSON is built on two structures:
A collection of name/value pairs.
In Python it is dict.
An ordered list of values.
In Python it is list.
An object is an unordered set of name/value pairs. An object begins with { (left brace) and ends with } (right brace). Each name is followed by : (colon) and the name/value pairs are separated by , (comma).
An array is an ordered collection of values. An array begins with [ (left bracket) and ends with ] (right bracket). Values are separated by , (comma).
A value can be a string in double quotes, or a number, or true or false or null, or an object or an array. These structures can be nested.
A string is a sequence of zero or more Unicode characters, wrapped in double quotes, using backslash escapes. A character is represented as a single character string. A string is very much like a C or Java string.
A number is very much like a C or Java number, except that the octal and hexadecimal formats are not used.
json module
Python has json module which follows general API as other Python serialization modules
Load JSON and convert to Python base type object:
json.loads(json_str)
Save Python object as JSON string:
json.dumps(some_object)
🪄 Code:
import json
a = [1, 2, "hello man!", [34, 56.5]]
b = dict(a=1, b=3, c=[1,2,3, 'hello'])
print(json.dumps(a))
json.dumps(b)
