DEV Community: Karthick Srinivasan

50 useful built-in modules in Python

Karthick Srinivasan — Thu, 05 Jan 2023 05:50:46 +0000

Here is a list of 50 useful built-in modules in Python:

sys - provides access to system-specific parameters and functions
os - provides functions for interacting with the operating system
math - provides mathematical functions
random - provides functions for generating random numbers
datetime - provides classes for working with dates and times
json - provides functions for working with JSON data
re - provides functions for working with regular expressions
urllib - provides functions for working with URLs
xml - provides functions for working with XML
email - provides functions for working with email messages
hashlib - provides functions for calculating hash values
hmac - provides functions for calculating HMAC values
itertools - provides functions for working with iterators
collections - provides additional data types for working with collections of data
heapq - provides functions for working with heaps
bisect - provides functions for working with sorted lists
array - provides functions for working with arrays
queue - provides thread-safe FIFO implementation
struct - provides pack and unpack functions for working with C-style data structures
threading - provides functions for working with threads
multipaddress - provides functions for working with IP addresses
subprocess - provides functions for working with subprocesses
tempfile - provides functions for working with temporary files and directories
shutil - provides functions for working with files and directories
glob - provides functions for working with file patterns
fnmatch - provides functions for matching file patterns
fnmatch - provides functions for matching file patterns
zipfile - provides functions for working with zip archives
tarfile - provides functions for working with tar archives
gzip - provides functions for working with gzip files
bz2 - provides functions for working with bzip2 files
lzma - provides functions for working with LZMA files
time - provides functions for working with time
calendar - provides functions for working with calendars
locale - provides functions for internationalization
gettext - provides functions for internationalization
locale - provides functions for internationalization
getopt - provides functions for parsing command-line options
argparse - provides functions for parsing command-line options
logging - provides functions for logging
logging.config - provides functions for configuring logging
logging.handlers - provides additional handler classes for logging
pprint - provides functions for pretty-printing data structures
cProfile - provides functions for profiling Python code
pstats - provides functions for working with profiling statistics
timeit - provides functions for measuring the execution time of small bits of Python code
trace - provides functions for tracing the execution of Python code
unittest - provides a unit testing framework
doctest - provides a framework for running tests embedded in documentation
unittest.mock - provides a library for testing in Python

Automating requests in postman which require Authorization

Karthick Srinivasan — Wed, 13 May 2020 05:59:20 +0000

If sending a request demands new authorization token each and every time, running the requests as a collection might be a little tricky.
Postman provides us an option to parameterize the access token generation process by adding a pre-request script and environment variables.

Parameterize the authorization at the collection level with the below code:

let tokenUrl = 'url';
let clientId = '<>';
let clientSecret = '<>';
let scope = '<>';

let getTokenRequest = {
    method: 'POST',
    url: tokenUrl,
    auth: {
        type: "basic",
        basic: [
            { key: "username", value: username },
            { key: "password", value: password }
        ]
    },
    body: {
        mode: 'urlencoded',
        urlencoded: [
            { key: 'grant_type', value: 'username' },
            { key: 'scope', value: scope }
        ]

    }

};

pm.sendRequest(getTokenRequest, (err, response) => {
    let jsonResponse = response.json(),
        newAccessToken = jsonResponse.access_token;

    console.log({ err, jsonResponse, newAccessToken })

    pm.globals.set('accessToken', newAccessToken);
    pm.environment.set('accessToken', newAccessToken);
    pm.variables.set('accessToken', newAccessToken);
});

Eclipse IDE Shortcuts - A quick reference guide

Karthick Srinivasan — Mon, 11 May 2020 10:05:25 +0000

Basic:

Ctrl + M - Max and Min the current window
Ctrl + Space - Intellisense (Autosuggestion)
Ctrl + 1 - Autocorrects and suggests more options (used mostly during compilation errors)
Alt + Up Arrow / Down arrow - to move a line up/down

Debug mode:

F5 - Go into the function (step into)
F6 - does the function call and goes to the next function(step over)
F8 - Go ahead and execute the rest of the program (used when step into sysout for eg.)
Inspect - to see what is the current value while debugging
Watch - add an expression like num * 3 or num * sum - to see what value it gives
Double click on a variable's value to change it during the execution
To activate conditional break point, double click on the break point in the breakpoint window and check 'conditional' and 
enter the condition in the text box below (use when we have to debug from the middle elements of an array)

Shortcuts:

Ctrl+Shift+L - to see the list of shortcuts in eclipse
Ctrl+Shift+R  - to search for any resource (for searching java classes and directly go there - just user written)
Ctrl+Shift+T - to search for any resource (for searching java classes and directly go there - user written + in built classes)
For the above two searches, just type the capital letters in the class, it will search quickly (For Eg. AL for ArrayList)
Ctrl+/ - Comment/uncomment the entire piece of code
F4 - Double click on a class name and press F4 to see the type hierarchy of classes in the type hierarchy window
(to see the inheritance relationships and all the methods it has)
Ctrl + T - to quickly see the type hierarchy of classes in the same window (doesn't show the methods that class has)
Ctrl + O - to quickly see the methods and variables that class has in the same window (doesn't show the type hierarchy of classes)
Ctrl + D - to delete the current line
Ctrl + L - to go to a particular line
Ctrl + Q - to got the point of last edit
F3 - place the cursor on a particular class and press F3 to go to that class (similar to Ctrl + Left click)
Toggle breadcrumbs - to see the complete path of a file (folder name, package name etc.--> shows jars as well)
Mark occurences - highlight a variable to see whereall it's used

Refractoring:

Ctrl+Shift+M - to extract a method seperately 
Ctrl+Shift+I - to inline that method (opposite of Ctrl+Shift+M)
Alt+Shift+R - to rename a variable and all it's references (use instead of find and replace)
Alt+Shift+L - to extract a local variable
Alt+Shift+I - to inline that variable (opposite of Alt+Shift+L)
Alt+Shift+T - to extract a constant (not a  direct shortcut)
Alt+Shift+C - to change the signature of a method (will add or remove the arguments and will pass the values provided wherever the method is called)
Alt+Shift+V - to move a method from one class to another class
Ctrl+Shift+F - to format the text

Code generation:

Alt+Shift+S - to generate getters and setters (not a  direct shortcut) - select the variables to just generate for the selected ones and not all
use the above shortcut to generate toString methods as well - we can select the required code style as well
use the above shortcut to generate equals and hashcode methods as well
use the above shortcut to generate constructors as well
use the above shortcut to generate override and implement methods as well

Auto formatting:

window-preferences-type 'format'-code style-format- customize the format
window-preferences-type 'save'- editor -save actions - select options accordingly to auto format whenever we save

Views:

Ctrl+Alt+H - to view call hierarchy (where the method is called)
F4 - to view type hierarchy

Handling Bootstrap Dropdowns in Selenium

Karthick Srinivasan — Sat, 09 May 2020 11:49:52 +0000

Handling dropdowns usually involves 4+ lines of code and there are chances of code duplication. Below is the code which makes it easier for us to handle all kinds of dropdowns (single select, multi select, starting with //select tag, starting with //div or other tags etc.) in 2 lines.

Below is the code:

package com.qa.TestCase;

import java.util.List;
import java.util.concurrent.TimeUnit;
import java.util.stream.Collectors;

import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.chrome.ChromeDriver;
import org.testng.annotations.Test;

import io.github.bonigarcia.wdm.WebDriverManager;

public class HandleBootStrapDropDownUsingStreams 
{
    public static WebDriver driver;

    @Test
    public void bootStrap() throws InterruptedException
    {
        WebDriverManager.chromedriver().setup();
        driver = new ChromeDriver();
        driver.manage().window().maximize();
        driver.manage().deleteAllCookies();

        driver.manage().timeouts().pageLoadTimeout(30, TimeUnit.SECONDS);
        driver.manage().timeouts().implicitlyWait(15, TimeUnit.SECONDS);

        driver.get("https://www.jquery-az.com/boots/demo.php?ex=63.0_2");

        driver.findElement(By.xpath("//button[@class='multiselect dropdown-toggle btn btn-default']")).click();

        By bootStrapDropDown = By.xpath("//ul[contains(@class,'multiselect-container')]//li//a//label");

        HandleBootStrapDropDownUsingStreams.printBootStrapDropDownValues(bootStrapDropDown);

        HandleBootStrapDropDownUsingStreams.selectValueFromBootStrapDropDown(bootStrapDropDown, "HTML");
        HandleBootStrapDropDownUsingStreams.selectValueFromBootStrapDropDown(bootStrapDropDown, "CSS");
        HandleBootStrapDropDownUsingStreams.selectValueFromBootStrapDropDown(bootStrapDropDown, "Angular");

    }

    //Function to Select a Value from BootStrap Drop Down using Streams.
    public static void selectValueFromBootStrapDropDown(By locator, String value)
    {
        List<WebElement> dropDownValues = driver.findElements(locator);
        dropDownValues.stream().filter(values -> values.getText().matches(value)).forEach(values -> values.click());
    }

    //Function to Print BootStrap Drop Down Values using Streams.
    public static void printBootStrapDropDownValues(By locator)
    {
        List<WebElement> dropDownValues = driver.findElements(locator);
        dropDownValues.stream().map(values -> values.getText()).collect(Collectors.toList()).forEach(values -> System.out.println(values));
    }
}

Downloading Maven jars inside a project folder

Karthick Srinivasan — Fri, 08 May 2020 08:27:35 +0000

Sometimes our environment will not support maven repo to download jars. So we can use our project's root directory as repo and add our jars over there by using the structure mentioned in the below in our pom.xml

<repository>
    <id>in-project</id>
    <name>In Project Repo</name>
    <url>file://${project.basedir}/libs</url>
</repository>

<dependency>
    <groupId>dropbox</groupId>
    <artifactId>dropbox-sdk</artifactId>
    <version>1.3.1</version>
</dependency>

Selenium Chrome (version 80 & 81) warnings

Karthick Srinivasan — Thu, 07 May 2020 13:37:51 +0000

Since the release of Chrome version 80, we all have been getting the 'Timeout warning'. It repeats itself until the browser is opened. Do you want to get rid of selenium chrome driver warnings?

Here is the simple solution.
Add the below line of code while setting up the driver properties.

System.setProperty("webdriver.chrome.silentOutput", "true");

It's a known bug in the versions 80&81 of Chrome browser. Though it will be fixed in upcoming releases, if you don't want to downgrade to version 79 or below, this will help.