10 расширений Chrome для повышения производительности на 269%

Я спросил: «Какие расширения для браузеров самые лучшие?»

Я получил более 50 ответов. Вот лучшие 10 из них.

Расширения для браузера — очень мощный инструмент.

Расширения могут не только обогатить ваш опыт просмотра веб-страниц, но и предоставить невероятную ценность, которая повысит вашу общую производительность.

Вот 10 расширений, которые должен попробовать каждый веб-разработчик:

  1. Wappalyzer :
    Каждый раз, когда я вижу веб-сайт, мне интересно, какой стек технологий «под капотом» управляет этим сайтом. Wappalyzer проверяет стек технологий, используемых на веб-сайте, и перечисляет их все. В нем перечислены внешние библиотеки, фреймворки, плагины, рекламные сети и все, что он может обнаружить. Это необходимо для веб-разработчиков.
  2. Потрясающие скриншоты:
    как веб-разработчики, мы должны постоянно делать скриншоты для различных целей. Awesome Screenshots позволяет нам легко делать снимки экрана браузера. Он имеет другие функции, такие как скриншоты на всю страницу, записи экрана, скриншоты пользовательских областей и т . Д.
  3. Палитра сайта:
    найти подходящую цветовую тему для веб-страницы довольно сложно. Если вам нравится цветовая тема определенного веб-сайта, вы можете скопировать эту тему с помощью этого расширения. Палитра сайта предоставляет все цветовые палитры сайта.
  4. Пользовательский Javascript и CSS :
    лично для меня это очень полезное расширение. Вы можете внедрить собственные CSS и JS в любой веб-сайт. Я использовал это расширение, чтобы скрыть {display: none} новостную ленту Facebook, а хэштеги отклонялись в Twitter. Потому что это раздражает меня
  5. SimpleScraper :
    это отличное расширение. Он позволяет разумно извлекать данные с любого веб-сайта и преобразовывать их в API или позволяет загружать их в нужном формате. Мне нравится это расширение по многим причинам 💞
  6. Octotree — Дерево кода Github :
    Octotree позволяет быстрее просматривать код в GitHub. Всякий раз, когда вы просматриваете репозиторий Github, вам приходится прыгать туда-сюда, чтобы понять код. Что делает octotree, так это то, что он перечисляет все файлы и папки в левой части браузера, что упрощает просмотр файлов проекта. Это экономит время ⌛
  7. Хранилище форм :
    вспомните последний момент «О, дерьмо», когда все, что вы вводили в онлайн-форму, было потеряно. Хранилище форм избавит вас от этого, хранилище форм позволяет сохранить форму, чтобы вам не пришлось снова заполнять форму из-за какой-то глупой ошибки. Form Vault экономит время ⭐⭐⭐⭐⭐
  8. Контрольный список веб-разработчика :
    это расширение напомнит вам о вещах и методах, которые вы можете упустить при создании веб-сайта. Он предупредит вас о поисковой оптимизации, медиа-запросах, Favicon и недружественных URL-адресах (мелочи, которые оказывают огромное влияние на посетителей сайта).
  9. JsonVue :
    JsonVue украсит JSON и сделает его читабельным и привлекательным для глаз 👀
  10. Temp Mail — одноразовая временная электронная почта :
    это очень полезный инструмент. Он предоставляет вам временную почту на определенное время, которую вы можете использовать, если не хотите, чтобы ваша электронная почта была в каком-либо информационном бюллетене.

Это 10 самых важных инструментов повышения производительности. Эти инструменты, которые я упомянул, очень полезны и экономят время.

Ссылка: https://medium.com/faun/10-chrome-extensions-to-boost-productivity-by-269-89bf78eeeae7

#chrome

What is GEEK

Buddha Community

10 расширений Chrome для повышения производительности на 269%

10 расширений Chrome для повышения производительности на 269%

Я спросил: «Какие расширения для браузеров самые лучшие?»

Я получил более 50 ответов. Вот лучшие 10 из них.

Расширения для браузера — очень мощный инструмент.

Расширения могут не только обогатить ваш опыт просмотра веб-страниц, но и предоставить невероятную ценность, которая повысит вашу общую производительность.

Вот 10 расширений, которые должен попробовать каждый веб-разработчик:

  1. Wappalyzer :
    Каждый раз, когда я вижу веб-сайт, мне интересно, какой стек технологий «под капотом» управляет этим сайтом. Wappalyzer проверяет стек технологий, используемых на веб-сайте, и перечисляет их все. В нем перечислены внешние библиотеки, фреймворки, плагины, рекламные сети и все, что он может обнаружить. Это необходимо для веб-разработчиков.
  2. Потрясающие скриншоты:
    как веб-разработчики, мы должны постоянно делать скриншоты для различных целей. Awesome Screenshots позволяет нам легко делать снимки экрана браузера. Он имеет другие функции, такие как скриншоты на всю страницу, записи экрана, скриншоты пользовательских областей и т . Д.
  3. Палитра сайта:
    найти подходящую цветовую тему для веб-страницы довольно сложно. Если вам нравится цветовая тема определенного веб-сайта, вы можете скопировать эту тему с помощью этого расширения. Палитра сайта предоставляет все цветовые палитры сайта.
  4. Пользовательский Javascript и CSS :
    лично для меня это очень полезное расширение. Вы можете внедрить собственные CSS и JS в любой веб-сайт. Я использовал это расширение, чтобы скрыть {display: none} новостную ленту Facebook, а хэштеги отклонялись в Twitter. Потому что это раздражает меня
  5. SimpleScraper :
    это отличное расширение. Он позволяет разумно извлекать данные с любого веб-сайта и преобразовывать их в API или позволяет загружать их в нужном формате. Мне нравится это расширение по многим причинам 💞
  6. Octotree — Дерево кода Github :
    Octotree позволяет быстрее просматривать код в GitHub. Всякий раз, когда вы просматриваете репозиторий Github, вам приходится прыгать туда-сюда, чтобы понять код. Что делает octotree, так это то, что он перечисляет все файлы и папки в левой части браузера, что упрощает просмотр файлов проекта. Это экономит время ⌛
  7. Хранилище форм :
    вспомните последний момент «О, дерьмо», когда все, что вы вводили в онлайн-форму, было потеряно. Хранилище форм избавит вас от этого, хранилище форм позволяет сохранить форму, чтобы вам не пришлось снова заполнять форму из-за какой-то глупой ошибки. Form Vault экономит время ⭐⭐⭐⭐⭐
  8. Контрольный список веб-разработчика :
    это расширение напомнит вам о вещах и методах, которые вы можете упустить при создании веб-сайта. Он предупредит вас о поисковой оптимизации, медиа-запросах, Favicon и недружественных URL-адресах (мелочи, которые оказывают огромное влияние на посетителей сайта).
  9. JsonVue :
    JsonVue украсит JSON и сделает его читабельным и привлекательным для глаз 👀
  10. Temp Mail — одноразовая временная электронная почта :
    это очень полезный инструмент. Он предоставляет вам временную почту на определенное время, которую вы можете использовать, если не хотите, чтобы ваша электронная почта была в каком-либо информационном бюллетене.

Это 10 самых важных инструментов повышения производительности. Эти инструменты, которые я упомянул, очень полезны и экономят время.

Ссылка: https://medium.com/faun/10-chrome-extensions-to-boost-productivity-by-269-89bf78eeeae7

#chrome

Connor Mills

Connor Mills

1670560264

Understanding Arrays in Python

Learn how to use Python arrays. Create arrays in Python using the array module. You'll see how to define them and the different methods commonly used for performing operations on them.
 

The artcile covers arrays that you create by importing the array module. We won't cover NumPy arrays here.

Table of Contents

  1. Introduction to Arrays
    1. The differences between Lists and Arrays
    2. When to use arrays
  2. How to use arrays
    1. Define arrays
    2. Find the length of arrays
    3. Array indexing
    4. Search through arrays
    5. Loop through arrays
    6. Slice an array
  3. Array methods for performing operations
    1. Change an existing value
    2. Add a new value
    3. Remove a value
  4. Conclusion

Let's get started!


What are Python Arrays?

Arrays are a fundamental data structure, and an important part of most programming languages. In Python, they are containers which are able to store more than one item at the same time.

Specifically, they are an ordered collection of elements with every value being of the same data type. That is the most important thing to remember about Python arrays - the fact that they can only hold a sequence of multiple items that are of the same type.

What's the Difference between Python Lists and Python Arrays?

Lists are one of the most common data structures in Python, and a core part of the language.

Lists and arrays behave similarly.

Just like arrays, lists are an ordered sequence of elements.

They are also mutable and not fixed in size, which means they can grow and shrink throughout the life of the program. Items can be added and removed, making them very flexible to work with.

However, lists and arrays are not the same thing.

Lists store items that are of various data types. This means that a list can contain integers, floating point numbers, strings, or any other Python data type, at the same time. That is not the case with arrays.

As mentioned in the section above, arrays store only items that are of the same single data type. There are arrays that contain only integers, or only floating point numbers, or only any other Python data type you want to use.

When to Use Python Arrays

Lists are built into the Python programming language, whereas arrays aren't. Arrays are not a built-in data structure, and therefore need to be imported via the array module in order to be used.

Arrays of the array module are a thin wrapper over C arrays, and are useful when you want to work with homogeneous data.

They are also more compact and take up less memory and space which makes them more size efficient compared to lists.

If you want to perform mathematical calculations, then you should use NumPy arrays by importing the NumPy package. Besides that, you should just use Python arrays when you really need to, as lists work in a similar way and are more flexible to work with.

How to Use Arrays in Python

In order to create Python arrays, you'll first have to import the array module which contains all the necassary functions.

There are three ways you can import the array module:

  1. By using import array at the top of the file. This includes the module array. You would then go on to create an array using array.array().
import array

#how you would create an array
array.array()
  1. Instead of having to type array.array() all the time, you could use import array as arr at the top of the file, instead of import array alone. You would then create an array by typing arr.array(). The arr acts as an alias name, with the array constructor then immediately following it.
import array as arr

#how you would create an array
arr.array()
  1. Lastly, you could also use from array import *, with * importing all the functionalities available. You would then create an array by writing the array() constructor alone.
from array import *

#how you would create an array
array()

How to Define Arrays in Python

Once you've imported the array module, you can then go on to define a Python array.

The general syntax for creating an array looks like this:

variable_name = array(typecode,[elements])

Let's break it down:

  • variable_name would be the name of the array.
  • The typecode specifies what kind of elements would be stored in the array. Whether it would be an array of integers, an array of floats or an array of any other Python data type. Remember that all elements should be of the same data type.
  • Inside square brackets you mention the elements that would be stored in the array, with each element being separated by a comma. You can also create an empty array by just writing variable_name = array(typecode) alone, without any elements.

Below is a typecode table, with the different typecodes that can be used with the different data types when defining Python arrays:

TYPECODEC TYPEPYTHON TYPESIZE
'b'signed charint1
'B'unsigned charint1
'u'wchar_tUnicode character2
'h'signed shortint2
'H'unsigned shortint2
'i'signed intint2
'I'unsigned intint2
'l'signed longint4
'L'unsigned longint4
'q'signed long longint8
'Q'unsigned long longint8
'f'floatfloat4
'd'doublefloat8

Tying everything together, here is an example of how you would define an array in Python:

import array as arr 

numbers = arr.array('i',[10,20,30])


print(numbers)

#output

#array('i', [10, 20, 30])

Let's break it down:

  • First we included the array module, in this case with import array as arr .
  • Then, we created a numbers array.
  • We used arr.array() because of import array as arr .
  • Inside the array() constructor, we first included i, for signed integer. Signed integer means that the array can include positive and negative values. Unsigned integer, with H for example, would mean that no negative values are allowed.
  • Lastly, we included the values to be stored in the array in square brackets.

Keep in mind that if you tried to include values that were not of i typecode, meaning they were not integer values, you would get an error:

import array as arr 

numbers = arr.array('i',[10.0,20,30])


print(numbers)

#output

#Traceback (most recent call last):
# File "/Users/dionysialemonaki/python_articles/demo.py", line 14, in <module>
#   numbers = arr.array('i',[10.0,20,30])
#TypeError: 'float' object cannot be interpreted as an integer

In the example above, I tried to include a floating point number in the array. I got an error because this is meant to be an integer array only.

Another way to create an array is the following:

from array import *

#an array of floating point values
numbers = array('d',[10.0,20.0,30.0])

print(numbers)

#output

#array('d', [10.0, 20.0, 30.0])

The example above imported the array module via from array import * and created an array numbers of float data type. This means that it holds only floating point numbers, which is specified with the 'd' typecode.

How to Find the Length of an Array in Python

To find out the exact number of elements contained in an array, use the built-in len() method.

It will return the integer number that is equal to the total number of elements in the array you specify.

import array as arr 

numbers = arr.array('i',[10,20,30])


print(len(numbers))

#output
# 3

In the example above, the array contained three elements – 10, 20, 30 – so the length of numbers is 3.

Array Indexing and How to Access Individual Items in an Array in Python

Each item in an array has a specific address. Individual items are accessed by referencing their index number.

Indexing in Python, and in all programming languages and computing in general, starts at 0. It is important to remember that counting starts at 0 and not at 1.

To access an element, you first write the name of the array followed by square brackets. Inside the square brackets you include the item's index number.

The general syntax would look something like this:

array_name[index_value_of_item]

Here is how you would access each individual element in an array:

import array as arr 

numbers = arr.array('i',[10,20,30])

print(numbers[0]) # gets the 1st element
print(numbers[1]) # gets the 2nd element
print(numbers[2]) # gets the 3rd element

#output

#10
#20
#30

Remember that the index value of the last element of an array is always one less than the length of the array. Where n is the length of the array, n - 1 will be the index value of the last item.

Note that you can also access each individual element using negative indexing.

With negative indexing, the last element would have an index of -1, the second to last element would have an index of -2, and so on.

Here is how you would get each item in an array using that method:

import array as arr 

numbers = arr.array('i',[10,20,30])

print(numbers[-1]) #gets last item
print(numbers[-2]) #gets second to last item
print(numbers[-3]) #gets first item
 
#output

#30
#20
#10

How to Search Through an Array in Python

You can find out an element's index number by using the index() method.

You pass the value of the element being searched as the argument to the method, and the element's index number is returned.

import array as arr 

numbers = arr.array('i',[10,20,30])

#search for the index of the value 10
print(numbers.index(10))

#output

#0

If there is more than one element with the same value, the index of the first instance of the value will be returned:

import array as arr 


numbers = arr.array('i',[10,20,30,10,20,30])

#search for the index of the value 10
#will return the index number of the first instance of the value 10
print(numbers.index(10))

#output

#0

How to Loop through an Array in Python

You've seen how to access each individual element in an array and print it out on its own.

You've also seen how to print the array, using the print() method. That method gives the following result:

import array as arr 

numbers = arr.array('i',[10,20,30])

print(numbers)

#output

#array('i', [10, 20, 30])

What if you want to print each value one by one?

This is where a loop comes in handy. You can loop through the array and print out each value, one-by-one, with each loop iteration.

For this you can use a simple for loop:

import array as arr 

numbers = arr.array('i',[10,20,30])

for number in numbers:
    print(number)
    
#output
#10
#20
#30

You could also use the range() function, and pass the len() method as its parameter. This would give the same result as above:

import array as arr  

values = arr.array('i',[10,20,30])

#prints each individual value in the array
for value in range(len(values)):
    print(values[value])

#output

#10
#20
#30

How to Slice an Array in Python

To access a specific range of values inside the array, use the slicing operator, which is a colon :.

When using the slicing operator and you only include one value, the counting starts from 0 by default. It gets the first item, and goes up to but not including the index number you specify.


import array as arr 

#original array
numbers = arr.array('i',[10,20,30])

#get the values 10 and 20 only
print(numbers[:2])  #first to second position

#output

#array('i', [10, 20])

When you pass two numbers as arguments, you specify a range of numbers. In this case, the counting starts at the position of the first number in the range, and up to but not including the second one:

import array as arr 

#original array
numbers = arr.array('i',[10,20,30])


#get the values 20 and 30 only
print(numbers[1:3]) #second to third position

#output

#rray('i', [20, 30])

Methods For Performing Operations on Arrays in Python

Arrays are mutable, which means they are changeable. You can change the value of the different items, add new ones, or remove any you don't want in your program anymore.

Let's see some of the most commonly used methods which are used for performing operations on arrays.

How to Change the Value of an Item in an Array

You can change the value of a specific element by speficying its position and assigning it a new value:

import array as arr 

#original array
numbers = arr.array('i',[10,20,30])

#change the first element
#change it from having a value of 10 to having a value of 40
numbers[0] = 40

print(numbers)

#output

#array('i', [40, 20, 30])

How to Add a New Value to an Array

To add one single value at the end of an array, use the append() method:

import array as arr 

#original array
numbers = arr.array('i',[10,20,30])

#add the integer 40 to the end of numbers
numbers.append(40)

print(numbers)

#output

#array('i', [10, 20, 30, 40])

Be aware that the new item you add needs to be the same data type as the rest of the items in the array.

Look what happens when I try to add a float to an array of integers:

import array as arr 

#original array
numbers = arr.array('i',[10,20,30])

#add the integer 40 to the end of numbers
numbers.append(40.0)

print(numbers)

#output

#Traceback (most recent call last):
#  File "/Users/dionysialemonaki/python_articles/demo.py", line 19, in <module>
#   numbers.append(40.0)
#TypeError: 'float' object cannot be interpreted as an integer

But what if you want to add more than one value to the end an array?

Use the extend() method, which takes an iterable (such as a list of items) as an argument. Again, make sure that the new items are all the same data type.

import array as arr 

#original array
numbers = arr.array('i',[10,20,30])

#add the integers 40,50,60 to the end of numbers
#The numbers need to be enclosed in square brackets

numbers.extend([40,50,60])

print(numbers)

#output

#array('i', [10, 20, 30, 40, 50, 60])

And what if you don't want to add an item to the end of an array? Use the insert() method, to add an item at a specific position.

The insert() function takes two arguments: the index number of the position the new element will be inserted, and the value of the new element.

import array as arr 

#original array
numbers = arr.array('i',[10,20,30])

#add the integer 40 in the first position
#remember indexing starts at 0

numbers.insert(0,40)

print(numbers)

#output

#array('i', [40, 10, 20, 30])

How to Remove a Value from an Array

To remove an element from an array, use the remove() method and include the value as an argument to the method.

import array as arr 

#original array
numbers = arr.array('i',[10,20,30])

numbers.remove(10)

print(numbers)

#output

#array('i', [20, 30])

With remove(), only the first instance of the value you pass as an argument will be removed.

See what happens when there are more than one identical values:


import array as arr 

#original array
numbers = arr.array('i',[10,20,30,10,20])

numbers.remove(10)

print(numbers)

#output

#array('i', [20, 30, 10, 20])

Only the first occurence of 10 is removed.

You can also use the pop() method, and specify the position of the element to be removed:

import array as arr 

#original array
numbers = arr.array('i',[10,20,30,10,20])

#remove the first instance of 10
numbers.pop(0)

print(numbers)

#output

#array('i', [20, 30, 10, 20])

Conclusion

And there you have it - you now know the basics of how to create arrays in Python using the array module. Hopefully you found this guide helpful.

You'll start from the basics and learn in an interacitve and beginner-friendly way. You'll also build five projects at the end to put into practice and help reinforce what you learned.

Thanks for reading and happy coding!

Original article source at https://www.freecodecamp.org

#python 

How to Create Arrays in Python

In this tutorial, you'll know the basics of how to create arrays in Python using the array module. Learn how to use Python arrays. You'll see how to define them and the different methods commonly used for performing operations on them.

This tutorialvideo on 'Arrays in Python' will help you establish a strong hold on all the fundamentals in python programming language. Below are the topics covered in this video:  
1:15 What is an array?
2:53 Is python list same as an array?
3:48  How to create arrays in python?
7:19 Accessing array elements
9:59 Basic array operations
        - 10:33  Finding the length of an array
        - 11:44  Adding Elements
        - 15:06  Removing elements
        - 18:32  Array concatenation
       - 20:59  Slicing
       - 23:26  Looping  


Python Array Tutorial – Define, Index, Methods

In this article, you'll learn how to use Python arrays. You'll see how to define them and the different methods commonly used for performing operations on them.

The artcile covers arrays that you create by importing the array module. We won't cover NumPy arrays here.

Table of Contents

  1. Introduction to Arrays
    1. The differences between Lists and Arrays
    2. When to use arrays
  2. How to use arrays
    1. Define arrays
    2. Find the length of arrays
    3. Array indexing
    4. Search through arrays
    5. Loop through arrays
    6. Slice an array
  3. Array methods for performing operations
    1. Change an existing value
    2. Add a new value
    3. Remove a value
  4. Conclusion

Let's get started!

What are Python Arrays?

Arrays are a fundamental data structure, and an important part of most programming languages. In Python, they are containers which are able to store more than one item at the same time.

Specifically, they are an ordered collection of elements with every value being of the same data type. That is the most important thing to remember about Python arrays - the fact that they can only hold a sequence of multiple items that are of the same type.

What's the Difference between Python Lists and Python Arrays?

Lists are one of the most common data structures in Python, and a core part of the language.

Lists and arrays behave similarly.

Just like arrays, lists are an ordered sequence of elements.

They are also mutable and not fixed in size, which means they can grow and shrink throughout the life of the program. Items can be added and removed, making them very flexible to work with.

However, lists and arrays are not the same thing.

Lists store items that are of various data types. This means that a list can contain integers, floating point numbers, strings, or any other Python data type, at the same time. That is not the case with arrays.

As mentioned in the section above, arrays store only items that are of the same single data type. There are arrays that contain only integers, or only floating point numbers, or only any other Python data type you want to use.

When to Use Python Arrays

Lists are built into the Python programming language, whereas arrays aren't. Arrays are not a built-in data structure, and therefore need to be imported via the array module in order to be used.

Arrays of the array module are a thin wrapper over C arrays, and are useful when you want to work with homogeneous data.

They are also more compact and take up less memory and space which makes them more size efficient compared to lists.

If you want to perform mathematical calculations, then you should use NumPy arrays by importing the NumPy package. Besides that, you should just use Python arrays when you really need to, as lists work in a similar way and are more flexible to work with.

How to Use Arrays in Python

In order to create Python arrays, you'll first have to import the array module which contains all the necassary functions.

There are three ways you can import the array module:

  • By using import array at the top of the file. This includes the module array. You would then go on to create an array using array.array().
import array

#how you would create an array
array.array()
  • Instead of having to type array.array() all the time, you could use import array as arr at the top of the file, instead of import array alone. You would then create an array by typing arr.array(). The arr acts as an alias name, with the array constructor then immediately following it.
import array as arr

#how you would create an array
arr.array()
  • Lastly, you could also use from array import *, with * importing all the functionalities available. You would then create an array by writing the array() constructor alone.
from array import *

#how you would create an array
array()

How to Define Arrays in Python

Once you've imported the array module, you can then go on to define a Python array.

The general syntax for creating an array looks like this:

variable_name = array(typecode,[elements])

Let's break it down:

  • variable_name would be the name of the array.
  • The typecode specifies what kind of elements would be stored in the array. Whether it would be an array of integers, an array of floats or an array of any other Python data type. Remember that all elements should be of the same data type.
  • Inside square brackets you mention the elements that would be stored in the array, with each element being separated by a comma. You can also create an empty array by just writing variable_name = array(typecode) alone, without any elements.

Below is a typecode table, with the different typecodes that can be used with the different data types when defining Python arrays:

TYPECODEC TYPEPYTHON TYPESIZE
'b'signed charint1
'B'unsigned charint1
'u'wchar_tUnicode character2
'h'signed shortint2
'H'unsigned shortint2
'i'signed intint2
'I'unsigned intint2
'l'signed longint4
'L'unsigned longint4
'q'signed long longint8
'Q'unsigned long longint8
'f'floatfloat4
'd'doublefloat8

Tying everything together, here is an example of how you would define an array in Python:

import array as arr 

numbers = arr.array('i',[10,20,30])


print(numbers)

#output

#array('i', [10, 20, 30])

Let's break it down:

  • First we included the array module, in this case with import array as arr .
  • Then, we created a numbers array.
  • We used arr.array() because of import array as arr .
  • Inside the array() constructor, we first included i, for signed integer. Signed integer means that the array can include positive and negative values. Unsigned integer, with H for example, would mean that no negative values are allowed.
  • Lastly, we included the values to be stored in the array in square brackets.

Keep in mind that if you tried to include values that were not of i typecode, meaning they were not integer values, you would get an error:

import array as arr 

numbers = arr.array('i',[10.0,20,30])


print(numbers)

#output

#Traceback (most recent call last):
# File "/Users/dionysialemonaki/python_articles/demo.py", line 14, in <module>
#   numbers = arr.array('i',[10.0,20,30])
#TypeError: 'float' object cannot be interpreted as an integer

In the example above, I tried to include a floating point number in the array. I got an error because this is meant to be an integer array only.

Another way to create an array is the following:

from array import *

#an array of floating point values
numbers = array('d',[10.0,20.0,30.0])

print(numbers)

#output

#array('d', [10.0, 20.0, 30.0])

The example above imported the array module via from array import * and created an array numbers of float data type. This means that it holds only floating point numbers, which is specified with the 'd' typecode.

How to Find the Length of an Array in Python

To find out the exact number of elements contained in an array, use the built-in len() method.

It will return the integer number that is equal to the total number of elements in the array you specify.

import array as arr 

numbers = arr.array('i',[10,20,30])


print(len(numbers))

#output
# 3

In the example above, the array contained three elements – 10, 20, 30 – so the length of numbers is 3.

Array Indexing and How to Access Individual Items in an Array in Python

Each item in an array has a specific address. Individual items are accessed by referencing their index number.

Indexing in Python, and in all programming languages and computing in general, starts at 0. It is important to remember that counting starts at 0 and not at 1.

To access an element, you first write the name of the array followed by square brackets. Inside the square brackets you include the item's index number.

The general syntax would look something like this:

array_name[index_value_of_item]

Here is how you would access each individual element in an array:

import array as arr 

numbers = arr.array('i',[10,20,30])

print(numbers[0]) # gets the 1st element
print(numbers[1]) # gets the 2nd element
print(numbers[2]) # gets the 3rd element

#output

#10
#20
#30

Remember that the index value of the last element of an array is always one less than the length of the array. Where n is the length of the array, n - 1 will be the index value of the last item.

Note that you can also access each individual element using negative indexing.

With negative indexing, the last element would have an index of -1, the second to last element would have an index of -2, and so on.

Here is how you would get each item in an array using that method:

import array as arr 

numbers = arr.array('i',[10,20,30])

print(numbers[-1]) #gets last item
print(numbers[-2]) #gets second to last item
print(numbers[-3]) #gets first item
 
#output

#30
#20
#10

How to Search Through an Array in Python

You can find out an element's index number by using the index() method.

You pass the value of the element being searched as the argument to the method, and the element's index number is returned.

import array as arr 

numbers = arr.array('i',[10,20,30])

#search for the index of the value 10
print(numbers.index(10))

#output

#0

If there is more than one element with the same value, the index of the first instance of the value will be returned:

import array as arr 


numbers = arr.array('i',[10,20,30,10,20,30])

#search for the index of the value 10
#will return the index number of the first instance of the value 10
print(numbers.index(10))

#output

#0

How to Loop through an Array in Python

You've seen how to access each individual element in an array and print it out on its own.

You've also seen how to print the array, using the print() method. That method gives the following result:

import array as arr 

numbers = arr.array('i',[10,20,30])

print(numbers)

#output

#array('i', [10, 20, 30])

What if you want to print each value one by one?

This is where a loop comes in handy. You can loop through the array and print out each value, one-by-one, with each loop iteration.

For this you can use a simple for loop:

import array as arr 

numbers = arr.array('i',[10,20,30])

for number in numbers:
    print(number)
    
#output
#10
#20
#30

You could also use the range() function, and pass the len() method as its parameter. This would give the same result as above:

import array as arr  

values = arr.array('i',[10,20,30])

#prints each individual value in the array
for value in range(len(values)):
    print(values[value])

#output

#10
#20
#30

How to Slice an Array in Python

To access a specific range of values inside the array, use the slicing operator, which is a colon :.

When using the slicing operator and you only include one value, the counting starts from 0 by default. It gets the first item, and goes up to but not including the index number you specify.

import array as arr 

#original array
numbers = arr.array('i',[10,20,30])

#get the values 10 and 20 only
print(numbers[:2])  #first to second position

#output

#array('i', [10, 20])

When you pass two numbers as arguments, you specify a range of numbers. In this case, the counting starts at the position of the first number in the range, and up to but not including the second one:

import array as arr 

#original array
numbers = arr.array('i',[10,20,30])


#get the values 20 and 30 only
print(numbers[1:3]) #second to third position

#output

#rray('i', [20, 30])

Methods For Performing Operations on Arrays in Python

Arrays are mutable, which means they are changeable. You can change the value of the different items, add new ones, or remove any you don't want in your program anymore.

Let's see some of the most commonly used methods which are used for performing operations on arrays.

How to Change the Value of an Item in an Array

You can change the value of a specific element by speficying its position and assigning it a new value:

import array as arr 

#original array
numbers = arr.array('i',[10,20,30])

#change the first element
#change it from having a value of 10 to having a value of 40
numbers[0] = 40

print(numbers)

#output

#array('i', [40, 20, 30])

How to Add a New Value to an Array

To add one single value at the end of an array, use the append() method:

import array as arr 

#original array
numbers = arr.array('i',[10,20,30])

#add the integer 40 to the end of numbers
numbers.append(40)

print(numbers)

#output

#array('i', [10, 20, 30, 40])

Be aware that the new item you add needs to be the same data type as the rest of the items in the array.

Look what happens when I try to add a float to an array of integers:

import array as arr 

#original array
numbers = arr.array('i',[10,20,30])

#add the integer 40 to the end of numbers
numbers.append(40.0)

print(numbers)

#output

#Traceback (most recent call last):
#  File "/Users/dionysialemonaki/python_articles/demo.py", line 19, in <module>
#   numbers.append(40.0)
#TypeError: 'float' object cannot be interpreted as an integer

But what if you want to add more than one value to the end an array?

Use the extend() method, which takes an iterable (such as a list of items) as an argument. Again, make sure that the new items are all the same data type.

import array as arr 

#original array
numbers = arr.array('i',[10,20,30])

#add the integers 40,50,60 to the end of numbers
#The numbers need to be enclosed in square brackets

numbers.extend([40,50,60])

print(numbers)

#output

#array('i', [10, 20, 30, 40, 50, 60])

And what if you don't want to add an item to the end of an array? Use the insert() method, to add an item at a specific position.

The insert() function takes two arguments: the index number of the position the new element will be inserted, and the value of the new element.

import array as arr 

#original array
numbers = arr.array('i',[10,20,30])

#add the integer 40 in the first position
#remember indexing starts at 0

numbers.insert(0,40)

print(numbers)

#output

#array('i', [40, 10, 20, 30])

How to Remove a Value from an Array

To remove an element from an array, use the remove() method and include the value as an argument to the method.

import array as arr 

#original array
numbers = arr.array('i',[10,20,30])

numbers.remove(10)

print(numbers)

#output

#array('i', [20, 30])

With remove(), only the first instance of the value you pass as an argument will be removed.

See what happens when there are more than one identical values:

import array as arr 

#original array
numbers = arr.array('i',[10,20,30,10,20])

numbers.remove(10)

print(numbers)

#output

#array('i', [20, 30, 10, 20])

Only the first occurence of 10 is removed.

You can also use the pop() method, and specify the position of the element to be removed:

import array as arr 

#original array
numbers = arr.array('i',[10,20,30,10,20])

#remove the first instance of 10
numbers.pop(0)

print(numbers)

#output

#array('i', [20, 30, 10, 20])

Conclusion

And there you have it - you now know the basics of how to create arrays in Python using the array module. Hopefully you found this guide helpful.

Thanks for reading and happy coding!

#python #programming 

Tyrique  Littel

Tyrique Littel

1603450800

Chrome 86 Aims to Bar Abusive Notification Content

Google has added a new feature to Chrome 86 that aims to stomp out abusive notification content.

Web notifications are utilized for a variety of applications – such as prompting site visitors to sign up for newsletters. However, they can also be misused for phishing, malware or fake messages that imitate system notifications for the purpose of generating user interactions. Google has taken steps to battle this issue by automatically blocking the web notifications that display abusive or misleading content.

When visitors encounter a webpage with malicious notification content, the webpage will be blocked and a Chrome alert on the upper navigation bar will warn them that the website might be trying to trick them into displaying intrusive notifications. It will ask them to “Continue Blocking” or “Allow” – the latter option will let users continue on to the webpage.

“Abusive notification prompts are one of the top user complaints we receive about Chrome,” according to PJ McLachlan, product manager with Google, on Wednesday. “Our goal with these changes is to improve the experience for Chrome users and to reduce the incentive for abusive sites to misuse the web-notifications feature.”

In order to detect sites that send abusive notification content, Google will first subscribe occasionally to website push notifications (if the push permission is requested) via its automated web crawling service.

Notifications that are sent to the automated Chrome instances will be evaluated for abusive content, and sites sending abusive notifications will be flagged for enforcement if the issue is unresolved, said Google.

When a site is found to be in “failing” status for any type of notification abuse, Google will send a warning email to the registered owners of the site 30 days before cracking down. During this time, websites can address the issue and request another review.

Google first implemented controls that went against abusive notifications with Chrome 80, when it introduced a “quiet notification permission UI [user interface]” feature. Then, in Chrome 84, it announced auto-enrollment in quiet notification UI for websites with abusive-notification permission requests, such as sites that use deceptive patterns to request notification permissions.

However, the new enforcement in Chrome 86 takes it a step further by focusing “on notification content and is triggered by sites that have a history of sending messages containing abusive content,” said Google. “This treatment applies to sites that try to trick users into accepting the notification permission for malicious purposes, for example sites that use web notifications to send malware or to mimic system messages to obtain user login credentials.”

In an upcoming release, Chrome will revert the notification permission status from “granted” to “default” for abusive origins, preventing further notifications unless the user returns to the abusive origin and re-enables them. That’s because “prior to the release of Chrome’s abusive notifications protections, many users have already unintentionally allowed notifications from websites engaging in abusive activity,” it said.

Google this week also warned of an update to its Chrome browser that patches a zero-day vulnerability in the software’s FreeType font rendering library that was actively being exploited in the wild.

#web security #abusive content #abusive notifications #blocking #browser #browser notifications #chrome 80 #chrome 84 #chrome 86 #google #google chrome #malicious notification #safe browsing #web security

Ethen Ellen

1619858914

AOL Emails Not Loading Problems (+1-888-857-5157) in Chrome Browser

This is image title
AOL Mail is one of the free email services that includes calendar management and task management. If your AOL Emails Not Loading Problems in Chrome Browser, try these troubleshooting steps which is mention below. In this post, we are trying to describe the reason behind AOL email not loading and how to resolve AOL mail loading issues.

3 Reason Behind AOL Emails Not Loading Problems

Reason #1. Whenever you are unable to receive the new emails into your computer. You should log into your AOL mail account and go to the settings and click on filter settings. Now check the account settings, if you find any filter. you need to click on delete. After deleting the settings, you should send a mail to yourself. Let’s see if you are receiving it now or not.

Reason #2. If you do not find any filters into your emails, you should check the block list settings, maybe you have blocked the new emails from senders. That’s why you are not receiving any new emails. so, you should immediately go ahead and check it.

Reason #3. If you are unable to receive the new emails into your phone or computer. I would like to suggest you to check the server settings. Most of the time, people are facing such kind of problem due to the incorrect server settings. So, you should check them properly and if you find something wrong over there. You need to remove the account from your computer or phone and then reconfigure it. It will start working fine.

How to Resolve AOL Emails Not Loading Problems in Chrome Browser

If Your AOL Emails Not Loading Problems in Chrome Browser then you can go and find a help to resolve this issue. To get through this problem, follow the instructions below:

Solution 1: Clear browsing data on Chrome

  • On your computer, launch the Google Chrome browser after assuring that you have a stable Internet connection.
  • Close all the browser tabs (if any) and open a new blank tab.
  • Click the Customize and control Google Chrome icon at the top-right corner and select the More tools option from the drop-down list.
  • In the pop-up window, navigate to the top-left corner and click the clear browsing data tab beneath History.
  • When you are asked to choose the time limit, choose the Time
  • After choosing all the data, click the Clear data button to remove all your Chrome browsing data.
  • Once you have removed all the browsing data, sign in to your AOL Mail.
  • If your AOL Mail is still not loading on Chrome, move on to the next solution.

Solution 2: Reset web settings

  • On your Chrome browser, stop all the running tabs and start a blank tab.
  • Navigate to the top-right corner of the tab and click the Customize and control Google Chrome icon (three vertical dots).
  • Click on Settings from the drop-down list.
  • Navigate to the bottom of the Settings page and click Advanced.
  • Click the Reset Settings tab twice underneath Reset and clean up.
  • Now, your Chrome browser will be restored to factory defaults.
  • Restart your Chrome browser and navigate to the official AOL site.
  • Enter the correct login credentials in the essential field and try signing in to your AOL email account.
    If AOL Mail is still not loading on Chrome, contact our technical support team by clicking the Call button available on this page for remote assistance.
    After this, if you are unable to resolve AOL emails loading problems in chrome browser, don’t be panic. Email Expert 24*7 team is here to resolve all AOL mail issues as soon as possible. Just Dial Customer Care Toll-Free Number: +1-888-857-5157 and get instant help. Our technical team’s services are available- 24x7.

Source: https://email-expert247.blogspot.com/2021/01/aol-emails-not-loading-problems-1-888.html

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