Python 3.8.5 : Testing with openpyxl - part 001 .

The Python executes the code line by line because is an interpreter language.
This allows users to solve issues in the programming area, fast and easy.
I use python versiono 3.8.5 build on Aug 12 2020 at 00:00:00, see the result of interactive mode:

[mythcat@desk ~]$ python
Python 3.8.5 (default, Aug 12 2020, 00:00:00) 
[GCC 10.2.1 20200723 (Red Hat 10.2.1-1)] on linux
Type "help", "copyright", "credits" or "license" for more information.

Today I will show you how to start using openpyxl python package.
Another tutorial about python and documents can be found here.
The openpyxl was created by Eric Gazoni, Charlie Clark, and is a Python library to read/write Excel 2010 xlsx/xlsm/xltx/xltm files.
Let's install the openpyxl python package:

[mythcat@desk ~]$ pip3 install openpyxl --user
Collecting openpyxl
...
Installing collected packages: openpyxl
Successfully installed openpyxl-3.0.5

I tested with the default example source code and works well.

from openpyxl import Workbook
wb = Workbook()

# grab the active worksheet
ws = wb.active

# Data can be assigned directly to cells
ws['A1'] = 42

# Rows can also be appended
ws.append([1, 2, 3])

# Python types will automatically be converted
import datetime
ws['A2'] = datetime.datetime.now()

# Save the file
wb.save("sample.xlsx")

The next example gets all data about asteroids close to planet Earth and put into xlsx file type.
The rows with dangerous asteroids are fill with the red color:

# check asteroids close to planet Earth and add it to file
# import json python package
import json, urllib.request, time

# import openpyxl python package
from openpyxl import Workbook
from openpyxl.styles import PatternFill
# use active worksheet
wb = Workbook()
ws = wb.active

today = time.strftime('%Y-%m-%d', time.gmtime())
print("Time is: " + today)
now = today
# retrieve data about asteroids approaching planet Earth into json format
url = "https://api.nasa.gov/neo/rest/v1/feed?start_date=" + today + "&end_date=" + today + "&api_key=DEMO_KEY"
response = urllib.request.urlopen(url)
result = json.loads(response.read())

print("Now, " + str(result["element_count"]) + " asteroids is close to planet Earth.")
asteroids = result["near_earth_objects"]

no_data = ""
dangerous = ""

ws.append(['today', 'name', 'dangerous?', 'no_data'])
# parsing all the JSON data and add to file
for asteroid in asteroids:
    for field in asteroids[asteroid]:

      try:
        name = "Asteroid Name: " + field["name"]

        if field["is_potentially_hazardous_asteroid"]:   
          dangerous = "... dangerous to planet Earth!"

        else:
          dangerous = "... not threat to planet Earth!"

      except:
        no_data = "no data"
      ws.append([today, name, dangerous, no_data]) 

# create a red patern to fill
redFill = PatternFill(start_color='FFFF0000',
                   end_color='FFFF0000',
                   fill_type='solid')

# check the row with the dangerous asteroid and fill it
for row in ws.rows:
 if row[2].value == "... dangerous to planet Earth!":
  for cell in row:
      cell.fill = redFill

# write all data to file 
wb.save(str(now)+"_asteroids.xlsx")

I run it and result working well:

[mythcat@desk ~]$ python asteroid_data.py 
Time is: 2020-08-23
Now, 9 asteroids is close to planet Earth.

... see the next screenshot:

Python 3.8.5 : Testing the pyre tool - part 001.

The Pyre is a static analysis tool to detect and prevent security issues in Python code that can be found on the official website.
The Pyre tool supports the Language Server Protocol and has an extension for VSCode.
The team development comes at August 7, 2020, with this intro:
Pyre is a performant type checker for Python. Statically typing what are essentially fully dynamic languages has a long tradition at Facebook. We've done this for PHP with Hack and for Javascript with Flow.
The install is easy to do with pip tool:

[mythcat@desk ~]$ pip install pyre-check
Defaulting to user installation because normal site-packages is not writeable
Collecting pyre-check
  Using cached pyre_check-0.0.52-py3-none-manylinux1_x86_64.whl (22.9 MB)
...
Installing collected packages: pyre-check
Successfully installed pyre-check-0.0.52

If you want to use a virtual environment:

[mythcat@desk ~]$ mkdir my_project && cd my_project
[mythcat@desk my_project]$ python3 -m venv ~/.venvs/venv
[mythcat@desk my_project]$ source ~/.venvs/venv/bin/activate
(venv) [mythcat@desk my_project]$ pip install pyre-check
Collecting pyre-check
...
(venv) [mythcat@desk my_project]$ pyre init
 ƛ Which directory should pyre be initialized in? (Default: `.`): 
(venv) [mythcat@desk my_project]$ cat .pyre_configuration
{
  "binary": "/home/mythcat/.venvs/venv/bin/pyre.bin",
  "source_directories": [
    "."
  ],
  "taint_models_path": "/home/mythcat/.venvs/venv/lib/pyre_check/taint/",
  "typeshed": "/home/mythcat/.venvs/venv/lib/pyre_check/typeshed/"
}
(venv) [mythcat@desk my_project]$ ls .pyre
my_project  pid_files  pyre.stderr
(venv) [mythcat@desk my_project]$ pyre
 ƛ No watchman binary found. 
To enable pyre incremental, you can install watchman: https://facebook.github.io/watchman/docs/install
 ƛ Defaulting to non-incremental check.
 ƛ No type errors found

Let's test with the default example from documentation:

(venv) [mythcat@desk my_project]$ echo "i: int = 'string'" > test.py
(venv) [mythcat@desk my_project]$ pyre
 ƛ No watchman binary found. 
To enable pyre incremental, you can install watchman: https://facebook.github.io/watchman/docs/install
 ƛ Defaulting to non-incremental check.
 ƛ Found 1 type error!
test.py:1:0 Incompatible variable type [9]: i is declared to have type `int` but is used as type `str`.
(venv) [mythcat@desk my_project]$ cat test.py 
i: int = 'string'

You can see is working well and detect the problem.
A short intro can found on the Facebook developers youtube channel:

Python 3.8.5 : The hashlib python package - part 001.

The tutorial for today is about hashlib python module.
The official webpage comes for this python package has this intro:
This module implements a common interface to many different secure hash and message digest algorithms. Included are the FIPS secure hash algorithms SHA1, SHA224, SHA256, SHA384, and SHA512 (defined in FIPS 180-2) as well as RSA’s MD5 algorithm (defined in Internet RFC 1321).
The example source code to test a simple hash is this:

import hashlib
import os

def file_sha1(filename):
    BUF_SIZE = 65536  # read stuff in 64kb chunks!
    get_sha1 = hashlib.sha1()
    with open(filename, 'rb') as f:
        while True:
            data = f.read(BUF_SIZE)
            if not data:
                break
            get_sha1.update(data)
    return get_sha1.hexdigest()

# I add this comment after first to see the hash difference.
files = [f for f in os.listdir('.') if os.path.isfile(f)]
for f in files:
    h = file_sha1(f)
    print(h) 

Let's test the source code with the default directory and two files.
I run it first with default source code and then I add a comment to test_hash_file.py file.
You can see the hash is changed from b222523567a8a806382b86578717ddbd00e0f4b4 to 2134660551cc67812413a3a75fd12efb05d591ef.

[mythcat@desk Projects_Python]$ ls
test_hash_file.py  test_numpy_001.py
[mythcat@desk Projects_Python]$ python test_hash_file.py 
98b2833527ad3d9fe263542c6aa06c04182d3dfb
b222523567a8a806382b86578717ddbd00e0f4b4
[mythcat@desk Projects_Python]$ python test_hash_file.py 
98b2833527ad3d9fe263542c6aa06c04182d3dfb
2134660551cc67812413a3a75fd12efb05d591ef

Python 3.8.5 : Pearson Product Moment Correlation with corrcoef from numpy.

The python package named numpy come with corrcoef function to return Pearson product-moment correlation coefficients.
This method has a limitation in that it can compute the correlation matrix between two variables only.
The full name is the Pearson Product Moment Correlation (PPMC).
The PPMC is not able to tell the difference between dependent variables and independent variables.
The documentation about this function can be found here.
More examples of Pearson Correlation can be found on this website.
My example presented in this tutorial, use the random packet to randomly generate integers and then calculate the correlation coefficients.
All of these are calculated five times in a for a cycle and each time the seed parameters are changed randomly.
Each time the correlation matrices are printed and then the random number graphs are displayed.
Let's see the source code:

import random

import numpy as np

nr_integers = 100
size_integers = 100

import matplotlib
import matplotlib.pyplot as plt

# set from 0 to 4 seed for random and show result 
for e in range(5):
    # change random seed
    np.random.seed(e)
    # nr_integers random integers between 0 and size_integers
    x = np.random.randint(0, size_integers, nr_integers)
    # Positive Correlation with some noise created with
    # nr_integers random integers between 0 and size_integers
    positive_y = x + np.random.normal(0, size_integers, nr_integers)
    correlation_positive = np.corrcoef(x, positive_y)
    # show matrix for correlation_positive
    print(correlation_positive)
    # Negative Correlation with same noise created with 
    # nr_integers random integers between 0 and size_integers
    negative_y = 100 - x + np.random.normal(0, size_integers, nr_integers)
    correlation_negative = np.corrcoef(x, negative_y)
    # show matrix for output with plt
    print(correlation_negative)
    # set graphic for plt with two graphics for each output with subplot
    plt.subplot(1, 2, 1)
    plt.scatter(x,positive_y)
    plt.subplot(1, 2, 2)
    plt.scatter(x,negative_y)
    # show the graph 
    plt.show()

Python 3.6.9 : My colab tutorials - part 008.

Today I deal with these two python packages named selenium and chromium-chromedriver.
I used selenium to get pieces of information from webpages.
These examples can be found at my GitHub project colab on the notebook named catafest_008.

Python 3.8.5 : PyEphem astronomy library for Python - part 001.

About this python package, you can find it from the official website.
PyEphem provides an ephem Python package for performing high-precision astronomy computations. The underlying numeric routines are coded in C and are the same ones that drive the popular XEphem astronomy application, whose author, Elwood Charles Downey, generously gave permission for their use in PyEphem. The name ephem is short for the word ephemeris, which is the traditional term for a table giving the position of a planet, asteroid, or comet for a series of dates.
Because I like astronomy and lately a lot has happened in this field, I thought I would come up with some simple tutorials for those who are interested.
This tutorial is tested on a Linux distribution called Fedora 32 with Python version 3.8.5.
I installed this python packet with the pip3 tool.

[mythcat@desk ~]$ sudo pip3 install ephem --user
WARNING: Running pip install with root privileges is generally not a good idea. 
Try `pip3 install --user` instead.
Collecting ephem
...
Installing collected packages: ephem
Successfully installed ephem-3.7.7.1

You know that NASA has launched the Mars Perseverance rover, so let's play with this topic a bit.
Let's see current azimuth and elevation for planet Mars.
For this is need the position of the observer and then is compute the position of the planet Mars.
I used the position of the Greenwich for the observer, but you can create your oun observer and use it.

[mythcat@desk ~]$ python3
Python 3.8.5 (default, Jul 20 2020, 00:00:00) 
[GCC 10.1.1 20200507 (Red Hat 10.1.1-1)] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import ephem
>>> import math
>>> convert = math.pi / 180.
>>> mars = ephem.Mars()
>>> greenwich = ephem.Observer()
>>> greenwich.lat = "51.477928"
>>> greenwich.lon = "-0.001545"
>>> mars.compute(greenwich)
>>> az_deg, alt_deg = mars.az*convert, mars.alt*convert
>>> print(f"Mars' current azimuth and elevation: {az_deg:.2f} {alt_deg:.2f}")
Mars' current azimuth and elevation: 0.11 -0.01

Let's see another example with Mars to take ascension and declination for the epoch specified:

...
>>> import datetime
>>> now = datetime.datetime.now()
>>> print(now)
2020-07-31 19:11:42.312027
>>> mars.compute(now)
>>> print(mars.ra)
1:12:43.64
>>> print(mars.dec)
3:33:22.6

You can get the magnitude, size (diameter in arcseconds) and size (radius as an angle):

>>> print(mars.mag)
-1.11
>>> print(mars.size)
14.555475234985352
>>> print(mars.radius)
0:00:07.3

You can easily see which constellation Mars is on.

>>> ephem.constellation(mars)
('Psc', 'Pisces')