Debbie Clay

Debbie Clay

1625539541

Writing a Python Script to Check If Any ACs Are Available Every 5 Minutes

It’s been ridiculously hot in Vancouver recently, and it’s almost impossible to find ACs.

So I wrote a simple Python script (with Selenium) to check if any AC’s are available at Best Buy every 5 minutes and mention me on Slack when there is one.

#python #selenium

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Writing a Python Script to Check If Any ACs Are Available Every 5 Minutes
Rupert Beatty

Rupert Beatty

1684202959

How to Check The Number Of Arguments in The Bash Script

It is essential to count the total number of arguments that are passed to the script for various purposes such as error handling, providing messages based on the number of arguments, and helping the user to pass the correct number of arguments. The total number of arguments can be counted in Bash in two ways. One is using “$#” and another by using a loop. The methods of checking the number of arguments and using this value for different purposes are shown in this tutorial.

Different Uses of Checking the Number of Arguments

The uses of checking the number of arguments are shown in this part of the tutorial using multiple examples.

Example 1: Count the Total Number of Arguments Using “$#”

Create a Bash file with the following script that counts the total number of arguments and print the argument values using a “for” loop.

#!/bin/bash

#Store the number of arguments

len=$#

echo "Total number of arguments: $len"

echo "Argument values are:"

#Print the argument values

for val in $@

do

echo $val

done

The following output appears after executing the script with the argument values of 67, 34, and 12:

Example 2: Print the Argument Values Based on the Argument Length

Create a Bash file with the following script that counts the total number of arguments and print the argument values based on the number of arguments. An error message is printed if no argument is passed to the script.

#!/bin/bash

#Store the number of arguments

len=$#

#check the total number of arguments

if [ $len -eq 0 ]; then

echo "No argument is given"

fi

#initialize the counter

counter=0

#Print argument value based on the counter value

while (( $counter < $len ))

do

if [ $counter -lt 1 ]; then

echo $1

elif [ $counter -lt 2 ]; then

echo $2

elif [ $counter -lt 3 ]; then

echo $3

fi

((counter++))

done

The script is executed four times in the output. The error message is printed when no argument is given. The argument values are printed when one, two, and three argument values are given.

Example 3: Calculate the Average of the Argument Values

Create a Bash file with the following script that counts the total number of arguments and print the average value of five argument values. The “bc” command is used in the script to calculate the average value. An error message is printed if no argument is passed to the script.

#!/bin/bash

#Check the total number of arguments

if [ $# -eq 5 ]; then

#Calculate the sum of the argument values

sum=$(($1+$2+$3+$4+$5))

#Calculate the average values

avg=$(($sum/5 | bc -l))

#Print the average values and the argument values

echo "Arguments values are: $1 $2 $3 $4 $5"

echo "Average value: $avg"

else

#Print error message

echo "Total number of arguments must be 5."

fi

The script is executed twice in the output. The error message is printed when no argument is given. The average of the argument values are printed when five argument values are given.

Example 4: Print the Error Message Based on the Argument Values

Create a Bash file with the following script that prints any of the three messages based on the “if” condition. The first “if” condition checks whether the number of arguments is 2 or not. The second “if” condition checks whether the length of the argument value is less than 5 or not. The third “if” condition checks whether the second argument is positive or not.

#!/bin/bash

#Read the argument values

name=$1

price=$2

#Count the length of the second argument

len=${#name}

#Check the total number of arguments

if [ $# -ne 2 ]; then

echo "Total number of arguments must be 2."

exit

#Check the length of the first argument

elif [ $len -lt 5 ]; then

echo "Product name must be minimum 5 characters long."

exit

#Check the value of the second argument

elif [ $2 -lt 0 ]; then

echo "The price value must be positive."

exit

fi

#Print the argument values

echo "The price of $name is TK. $price"

The script is executed four times in the output. The error message, “Total number of arguments must be 2”, is printed when no argument is given. The error message, “Product name must be minimum 5 characters long”, is printed when the length of the first argument is less than five. The error message, “The price value must be positive”, is printed when the second argument is negative.

Conclusion

The uses of the number of arguments in the Bash script for various purposes are shown in this tutorial using multiple examples to help the new Bash users.

Original article source at: https://linuxhint.com/

#bash #script #number #arguments 

Rupert Beatty

Rupert Beatty

1684207573

How to Check If The File Exists in Bash

Different types of files are used in Bash for different purposes. Many options are available in Bash to check if the particular file exists or not. The existence of the file can be checked using the file test operators with the “test” command or without the “test” command. The purposes of different types of file test operators to check the existence of the file are shown in this tutorial.

File Test Operators

Many file test operators exist in Bash to check if a particular file exists or not. Some of them are mentioned in the following:

OperatorPurpose
-fIt is used to check if the file exists and if it is a regular file.
-dIt is used to check if the file exists as a directory.
-eIt is used to check the existence of the file only.
-h or -LIt is used to check if the file exists as a symbolic link.
-rIt is used to check if the file exists as a readable file.
-wIt is used to check if the file exists as a writable file.
-xIt is used to check if the file exists as an executable file.
-sIt is used to check if the file exists and if the file is nonzero.
-bIt is used to check if the file exists as a block special file.
-cIt is used to check if the file exists as a special character file.

Different Examples to Check Whether the File Exists or Not

Many ways of checking the existence of the regular file are shown in this part of the tutorial.

Example 1: Check the Existence of the File Using the -F Operator with Single Third Brackets ([])

Create a Bash file with the following script that takes the filename from the user and check whether the file exists in the current location or not using the -f operator in the “if” condition with the single third brackets ([]).

#!/bin/bash

#Take the filename

echo -n "Enter the filename: "

read filename

#Check whether the file exists or not using the -f operator

if [ -f "$filename" ]; then

echo "File exists."

else

echo "File does not exist."

fi

The script is executed twice in the following script. The non-existence filename is given in the first execution. The existing filename is given in the second execution. The “ls” command is executed to check whether the file exists or not.

Example 2: Check the Existence of the File Using the -F Operator with Double Third Brackets ([[ ]])

Create a Bash file with the following script that takes the filename as a command-line argument and check whether the file exists in the current location or not using the -f operator in the “if” condition with the double third brackets ([[ ]]).

#!/bin/bash

#Take the filename from the command-line argument

filename=$1

#Check whether the argument is missing or not

if [ "$filename" != "" ]; then

#Check whether the file exists or not using the -f operator

if [[ -f "$filename" ]]; then

echo "File exists."

else

echo "File does not exist."

fi

else

echo "Argument is missing."

fi

The script is executed twice in the following script. No argument is given in the first execution. An existing filename is given as an argument in the second execution. The “ls” command is executed to check whether the file exists or not.

Example 3: Check the Existence of the File Using the -F Operator with the “Test” Command

Create a Bash file with the following script that takes the filename as a command-line argument and check whether the file exists in the current location or not using the -f operator with the “test” command in the “if” condition.

#!/bin/bash

#Take the filename from the command-line argument

filename=$1

#Check whether the argument is missing or not

if [ $# -lt 1 ]; then

echo "No argument is given."

exit 1

fi

#Check whether the file exists or not using the -f operator

if test -f "$filename"; then

echo "File exists."

else

echo "File does not exist."

fi

The script is executed twice in the following script. No argument is given in the first execution. An existing filename is given in the second execution.

Example 4: Check the Existence of the File with the Path

Create a Bash file with the following script that checks whether the file path exists or not using the -f operator with the “test” command in the “if” condition.

#!/bin/bash

#Set the filename with the directory location

filename='temp/courses.txt'

#Check whether the file exists or not using the -f operator

if test -f "$filename"; then

echo "File exists."

else

echo "File does not exist."

fi

The following output appears after executing the script:

Conclusion

The methods of checking whether a regular file exists or not in the current location or the particular location are shown in this tutorial using multiple examples.

Original article source at: https://linuxhint.com/

#bash #file 

Shardul Bhatt

Shardul Bhatt

1626775355

Why use Python for Software Development

No programming language is pretty much as diverse as Python. It enables building cutting edge applications effortlessly. Developers are as yet investigating the full capability of end-to-end Python development services in various areas. 

By areas, we mean FinTech, HealthTech, InsureTech, Cybersecurity, and that's just the beginning. These are New Economy areas, and Python has the ability to serve every one of them. The vast majority of them require massive computational abilities. Python's code is dynamic and powerful - equipped for taking care of the heavy traffic and substantial algorithmic capacities. 

Programming advancement is multidimensional today. Endeavor programming requires an intelligent application with AI and ML capacities. Shopper based applications require information examination to convey a superior client experience. Netflix, Trello, and Amazon are genuine instances of such applications. Python assists with building them effortlessly. 

5 Reasons to Utilize Python for Programming Web Apps 

Python can do such numerous things that developers can't discover enough reasons to admire it. Python application development isn't restricted to web and enterprise applications. It is exceptionally adaptable and superb for a wide range of uses.

Robust frameworks 

Python is known for its tools and frameworks. There's a structure for everything. Django is helpful for building web applications, venture applications, logical applications, and mathematical processing. Flask is another web improvement framework with no conditions. 

Web2Py, CherryPy, and Falcon offer incredible capabilities to customize Python development services. A large portion of them are open-source frameworks that allow quick turn of events. 

Simple to read and compose 

Python has an improved sentence structure - one that is like the English language. New engineers for Python can undoubtedly understand where they stand in the development process. The simplicity of composing allows quick application building. 

The motivation behind building Python, as said by its maker Guido Van Rossum, was to empower even beginner engineers to comprehend the programming language. The simple coding likewise permits developers to roll out speedy improvements without getting confused by pointless subtleties. 

Utilized by the best 

Alright - Python isn't simply one more programming language. It should have something, which is the reason the business giants use it. Furthermore, that too for different purposes. Developers at Google use Python to assemble framework organization systems, parallel information pusher, code audit, testing and QA, and substantially more. Netflix utilizes Python web development services for its recommendation algorithm and media player. 

Massive community support 

Python has a steadily developing community that offers enormous help. From amateurs to specialists, there's everybody. There are a lot of instructional exercises, documentation, and guides accessible for Python web development solutions. 

Today, numerous universities start with Python, adding to the quantity of individuals in the community. Frequently, Python designers team up on various tasks and help each other with algorithmic, utilitarian, and application critical thinking. 

Progressive applications 

Python is the greatest supporter of data science, Machine Learning, and Artificial Intelligence at any enterprise software development company. Its utilization cases in cutting edge applications are the most compelling motivation for its prosperity. Python is the second most well known tool after R for data analytics.

The simplicity of getting sorted out, overseeing, and visualizing information through unique libraries makes it ideal for data based applications. TensorFlow for neural networks and OpenCV for computer vision are two of Python's most well known use cases for Machine learning applications.

Summary

Thinking about the advances in programming and innovation, Python is a YES for an assorted scope of utilizations. Game development, web application development services, GUI advancement, ML and AI improvement, Enterprise and customer applications - every one of them uses Python to its full potential. 

The disadvantages of Python web improvement arrangements are regularly disregarded by developers and organizations because of the advantages it gives. They focus on quality over speed and performance over blunders. That is the reason it's a good idea to utilize Python for building the applications of the future.

#python development services #python development company #python app development #python development #python in web development #python software development

Art Lind

Art Lind

1602968400

Python Tricks Every Developer Should Know

Python is awesome, it’s one of the easiest languages with simple and intuitive syntax but wait, have you ever thought that there might ways to write your python code simpler?

In this tutorial, you’re going to learn a variety of Python tricks that you can use to write your Python code in a more readable and efficient way like a pro.

Let’s get started

Swapping value in Python

Instead of creating a temporary variable to hold the value of the one while swapping, you can do this instead

>>> FirstName = "kalebu"
>>> LastName = "Jordan"
>>> FirstName, LastName = LastName, FirstName 
>>> print(FirstName, LastName)
('Jordan', 'kalebu')

#python #python-programming #python3 #python-tutorials #learn-python #python-tips #python-skills #python-development

Козлова Люся Андреевна

Козлова Люся Андреевна

1684215440

Как проверить, существует ли файл в Bash

Различные типы файлов используются в Bash для разных целей. В Bash доступно множество опций, позволяющих проверить, существует ли конкретный файл или нет. Существование файла можно проверить с помощью операторов проверки файлов с командой «test» или без команды «test». В этом руководстве показаны цели различных типов операторов проверки файлов для проверки существования файла.

Операторы проверки файлов

В Bash существует множество операторов проверки файлов, чтобы проверить, существует ли конкретный файл или нет. Некоторые из них упоминаются в следующем:

ОператорЦель
-fОн используется для проверки того, существует ли файл и является ли он обычным файлом.
-дОн используется для проверки существования файла в виде каталога.
-еОн используется только для проверки существования файла.
-ч или -лОн используется для проверки существования файла в виде символической ссылки.
-рОн используется для проверки того, существует ли файл как читаемый файл.
-wОн используется для проверки того, существует ли файл как файл, доступный для записи.
-ИксОн используется для проверки того, существует ли файл как исполняемый файл.
-сОн используется для проверки того, существует ли файл и не равен ли он нулю.
-бОн используется для проверки того, существует ли файл в виде специального блочного файла.
-сОн используется для проверки того, существует ли файл как файл со специальными символами.

Различные примеры проверки существования файла

В этой части руководства показано множество способов проверки существования обычного файла.

Пример 1. Проверка существования файла с помощью оператора -F с одиночными третьими скобками ([])

Создайте файл Bash со следующим сценарием, который берет имя файла от пользователя и проверяет, существует ли файл в текущем местоположении или нет, используя оператор -f в условии «если» с одной третьей скобкой ([]).

#!/bin/bash

#Take the filename

echo -n "Enter the filename: "

read filename

#Check whether the file exists or not using the -f operator

if [ -f "$filename" ]; then

echo "File exists."

else

echo "File does not exist."

fi

Сценарий выполняется дважды в следующем сценарии. Несуществующее имя файла дается при первом выполнении. Существующее имя файла дается во втором исполнении. Команда «ls» выполняется, чтобы проверить, существует ли файл или нет.

Пример 2. Проверка существования файла с помощью оператора -F с двойными третьими скобками ([[ ]])

Создайте файл Bash со следующим сценарием, который принимает имя файла в качестве аргумента командной строки и проверяет, существует ли файл в текущем местоположении или нет, используя оператор -f в условии «если» с двойными третьими скобками ([[] ]).

#!/bin/bash

#Take the filename from the command-line argument

filename=$1

#Check whether the argument is missing or not

if [ "$filename" != "" ]; then

#Check whether the file exists or not using the -f operator

if [[ -f "$filename" ]]; then

echo "File exists."

else

echo "File does not exist."

fi

else

echo "Argument is missing."

fi

Сценарий выполняется дважды в следующем сценарии. При первом выполнении аргумент не передается. Существующее имя файла задается в качестве аргумента при втором выполнении. Команда «ls» выполняется, чтобы проверить, существует ли файл или нет.

Пример 3: Проверка существования файла с помощью оператора -F с командой «Тест»

Создайте файл Bash со следующим сценарием, который принимает имя файла в качестве аргумента командной строки и проверяет, существует ли файл в текущем местоположении или нет, используя оператор -f с командой «test» в условии «if».

#!/bin/bash

#Take the filename from the command-line argument

filename=$1

#Check whether the argument is missing or not

if [ $# -lt 1 ]; then

echo "No argument is given."

exit 1

fi

#Check whether the file exists or not using the -f operator

if test -f "$filename"; then

echo "File exists."

else

echo "File does not exist."

fi

Сценарий выполняется дважды в следующем сценарии. При первом выполнении аргумент не передается. Существующее имя файла дается во втором исполнении.

Пример 4. Проверка существования файла с указанием пути

Создайте файл Bash со следующим скриптом, который проверяет, существует ли путь к файлу или нет, используя оператор -f с командой «test» в условии «if».

#!/bin/bash

#Set the filename with the directory location

filename='temp/courses.txt'

#Check whether the file exists or not using the -f operator

if test -f "$filename"; then

echo "File exists."

else

echo "File does not exist."

fi

После выполнения скрипта появляется следующий вывод:

Заключение

Методы проверки того, существует ли обычный файл в текущем местоположении или в конкретном месте, показаны в этом руководстве с использованием нескольких примеров.

Оригинальный источник статьи: https://linuxhint.com/

#bash #file