## What are Membership Operators in Python

The membership operators are, as the name explains, used to verify a value membership. The operators are used to figure out if there are two forms of value as a part of a sequence, such as string or list membership operators: in and not in. To check whether two variables point to the same location or not, identity operators are used. Two forms of identity operators are is and is not. In general, operators are used to work on Python values and variables. These are regular symbols used for logical and arithmetical operations.Identity Operators: The Python identity operators are used to figure out whether a value is of a certain class or type. Typically, they are used for evaluating the type of information in a given variable. For example, to make sure you work with the variable type, you can combine identity operators with the built-in type() function. Python’s two identity operators are (is, is not).is: When evaluated, is Operator in Python returns true if the variables point to the same variable on either side of the operator and return false otherwise. Example 1: x = 5  if (type(x) is int):  print(“true”)  else:  print(“false”) Output: true Example 2: x =6  if(type(x) is int):  print("true")  else:  print("false") Output: true Example 3: list1 = [9, 8, 7, ‘i’]  list2 = list1  if list1 is list2:  print(“True”)  else:  print(“False”) Output: True The output here is true because list2 also refers to a list1 referenced by the variable list1. We may also use the is operator to verify if two python objects of the same type have other functions such as the type() function. is not: The operator ‘is not’ is the exact opposite of ‘is operator’ in Python. When evaluated, the operator returns false if the variables point to the same object on either side of the operator and return true otherwise. Example 1: x = 5.2  if (type(x) is not int):  print(“true”)  else:  print(“false”) Output: true Example 2: x =7.2  if(type(x) is not int):  print("true")  else:  print("false") Output: true Example 3: new_list = [9,8,7, 'i']  new_tuple = (9,8,7, 'i')  type(my_new_tuple)  if type(my_new_list) is not type(my_new_tuple):      print('True!, They are not of the same type')  else:      print("False, They are the same type") Output: True!, They are not of the same type Since the tuple and the list are not the same and the operator does not check their inequality, it returns True. Let us see a combined example of “is” and “is not”. Example: x = "identity operator"  if (type(x) is str):       print ("This is a string")   else:       print ("This is not a string")   y=987  if (type(y) is not str):       print ("This is a string")   else:       print ("This is not a string") Output: This is a string  This is not string Declare the value for variable x and y. Use the operator “is” to check if the value of x is the same as y. Next, we use the operator “is not” to check if the value of x is not the same as y. Example 2: a1 = 10  b1 = 10  a2 = ‘PythonProgramming’  b2 = ‘Programming’  a3 = [1,2,6]  b3 = [1,2,3]  print(a1 is not b1)  print(a2 is b2)  print(a3 is b3) Output: True  False  False Membership Operators: These operators evaluate membership in lists, sequences, or tuples in one sequence. In Python, there are two membership operators. (in, not in). It displays the result in the given sequence or string centred on the present variable.Membership Operators as a whole comprise a number of different operators. in Operator: It tests whether or not the value is present in the data sequence. It analyses the true value if the component is in the series and the false value if the component is not present.  Example 1: list1 = ['Aman', 'Bhuvan', 'Ashok', 'Vijay', 'Anil']  if 'Aman' in list1: print('Name Aman exists in list1') Output: Name Aman exists in list1 Example 2: list1=[1,2,4,5]  list2=[6,7,9]  for item in list1:  if item in list2:  print("overlapping")      else:  print("not overlapping") Output: not overlapping Example 3: new_list = [1,2,3,'a']  # loop around the list  for i in new_list:      print(i) Output: 1  2  3  a The in operator allows the variable i to refer to every element in the list iterated by the for loop. You have to think that the operator is used to check whether or not an element is present in a sequence, but what exactly happens? Well, when used in various ways, in a loop and in a conditional statement like if statement, the operator behaves differently. Let us remove the in operator in the example and modify it. Example: def overlapping(list1,list2):  c=0  d=0  for i in list1:  c+=1  for i in list2:  d+=1  for i in range(0,c):  for j in range(0,d):  if(list1[i]==list2[j]):  return1  return 0  list1=[1,2,3,4,5]  list2=[6,7,8,9]  if(overlapping(list1,list2)):  print("overlapping")  else:  print("not overlapping")  Output: not overlapping not in Operator: This operator verifies that a value is not present in a sequence. This is exactly contrary to the in operator. It evaluates to true when the element is not found or missing from the sequence and returns false when the element is found in the data sequence. The searchable element is the left operand and the right operand is the sequence in which it is searched. Example 1: x = 'Hello world'  y = {1:'a',2:'b'}  print('H' in x)  print('hello' not in x)  print(1 in y)  print('a' in y) Output: True  True  True  False Example 2: list=[10, 20, 30, 40, 50];  if( x not in list):  print("x is NOT present in the given list")  else:  print("x is present in the given list")  if( y in list):  print("y is present in the given list")  else:  print("y is NOT present in the given list") Output: x is NOT present in the given list  y is present in the given listExample 3: my_new_list = [1,2,3, 'a']  event = 'Studytonight'  if event not in my_new_list:      print('True') Output: True event not in my_new_list returns the negation of the in operator. The if condition checks if the special variable is included in the list or not. Since the special element isn’t in the list, it will return true. Example 4: list_one = [1, 2, 3]  list_two = [1, 2, 3]  list_one is not list_two Output: True This is because the lists apply to different objects in different memory locations.Conclusion: Identity and membership operators are useful to verify certain elements in a series of data and to verify the data identity respectively. Identity operators can be used with the type() function to check if a variable is of a certain type or class prior to any operation.

# What are Membership Operators in Python

5K
• by Abhresh S
• 24th Mar, 2021
• Last updated on 24th Mar, 2021

The membership operators are, as the name explains, used to verify a value membership. The operators are used to figure out if there are two forms of value as a part of a sequence, such as string or list membership operators:in and not in.

To check whether two variables point to the same location or not, identity operators are used. Two forms of identity operators are is and is not.

In general, operators are used to work on Python values and variables. These are regular symbols used for logical and arithmetical operations.

### Identity Operators:

The Python identity operatorsare used to figure out whether a value is of a certain class or type. Typically, they are used for evaluating the type of information in a given variable. For example, to make sure you work with the variable type, you can combine identity operators with the built-in type() function. Python’s two identity operators are (is, is not).

is:When evaluated, is Operator in Python returns true if the variables point to the same variable on either side of the operator and return false otherwise.

Example 1:

x = 5
if (type(x) is int):
print(“true”)
else:
print(“false”) 

Output:

true

Example 2:

x =6
if(type(x) is int):
print("true")
else:
print("false") 

Output:

true

Example 3:

list1 = [9, 8, 7, ‘i’]
list2 = list1
if list1 is list2:
print(“True”)
else:
print(“False”) 

Output:

True

The output here is true because list2 also refers to a list1referenced by the variable list1. We may also use the isoperator to verify if two python objects of the same type have other functions such as the type() function.

is not:The operator is not is the exact opposite of ‘is operator’in Python. When evaluated, the operator returns false if the variables point to the same object on either side of the operator and return trueotherwise.

Example 1:

x = 5.2
if (type(x) is not int):
print(“true”)
else:
print(“false”) 

Output:

true

Example 2:

x =7.2
if(type(x) is not int):
print("true")
else:
print("false") 

Output:

true

Example 3:

new_list = [9,8,7, 'i']
new_tuple = (9,8,7, 'i')
type(my_new_tuple)
if type(my_new_list) is not type(my_new_tuple):
print('True!, They are not of the same type')
else:
print("False, They are the same type") 

Output:

True!, They are not of the same type

Since the tuple and the list are not the same and the operator does not check their inequality, it returns True.

Let us see a combined example of “is” and “is not”.

Example:

x = "identity operator"
if (type(x) is str):
print ("This is a string")
else:
print ("This is not a string")
y=987
if (type(y) is not str):
print ("This is a string")
else:
print ("This is not a string") 

Output:

This is a string
This is not string 

Declare the value for variable x and y. Use the operator “is” to check if the value of x is the same as y. Next, we use the operator “is not” to check if the value of x is not the same as y.

Example 2:

a1 = 10
b1 = 10
a2 = ‘PythonProgramming’
b2 = ‘Programming’
a3 = [1,2,6]
b3 = [1,2,3]
print(a1 is not b1)
print(a2 is b2)
print(a3 is b3) 

Output:

True
False
False 

### Membership Operators:

These operators evaluate membership in lists, sequences, or tuples in one sequence. In Python, there are two membership operators. (in, not in). It displays the result in the given sequence or string centred on the present variable.

Membership Operators as a whole comprise a number of different operators.

in Operator:It tests whether or not the value is present in the data sequence. It analyses the true value if the component is in the series and the false value if the component is not present.

Example 1:

list1 = ['Aman', 'Bhuvan', 'Ashok', 'Vijay', 'Anil']
if 'Aman' in list1: print('Name Aman exists in list1') 

Output:

Name Aman exists in list1

Example 2:

list1=[1,2,4,5]
list2=[6,7,9]
for item in list1:
if item in list2:
print("overlapping")
else:
print("not overlapping") 

Output:

not overlapping

Example 3:

new_list = [1,2,3,'a']
# loop around the list
for i in new_list:
print(i) 

Output:

1
2
3
a 

The in operator allows the variable ito refer to every element in the list iterated by the for loop. You have to think that the operator is used to check whether or not an element is present in a sequence, but what exactly happens? Well, when used in various ways, in a loop and in a conditional statement like if statement, the operator behaves differently.

Let us remove the in operator in the example and modify it.

Example:

def overlapping(list1,list2):
c=0
d=0
for i in list1:
c+=1
for i in list2:
d+=1
for i in range(0,c):
for j in range(0,d):
if(list1[i]==list2[j]):
return1
return 0
list1=[1,2,3,4,5]
list2=[6,7,8,9]
if(overlapping(list1,list2)):
print("overlapping")
else:
print("not overlapping")  

Output:

not overlapping

not in Operator:This operatorverifies that a value is not present in a sequence. This is exactly contrary to the inoperator. It evaluates to true when the element is not found or missing from the sequence and returns false when the element is found in the data sequence. The searchable element is the left operand and the right operand is the sequence in which it is searched.

Example 1:

x = 'Hello world'
y = {1:'a',2:'b'}
print('H' in x)
print('hello' not in x)
print(1 in y)
print('a' in y) 

Output:

True
True
True
False 

Example 2:

list=[10, 20, 30, 40, 50];
if( x not in list):
print("x is NOT present in the given list")
else:
print("x is present in the given list")
if( y in list):
print("y is present in the given list")
else:
print("y is NOT present in the given list") 

Output:

x is NOT present in the given list
y is present in the given list

Example 3:

my_new_list = [1,2,3, 'a']
event = 'Studytonight'
if event not in my_new_list:
print('True') 

Output:

True

event not inmy_new_listreturns the negation of the in operator. The ifconditionchecks if the special variable is included in the list or not. Since the special element isn’t in the list, it will return true.

Example 4:

list_one = [1, 2, 3]
list_two = [1, 2, 3]
list_one is not list_two 

Output:

True

This is because the lists apply to different objects in different memory locations.

Conclusion:

Identity and membership operators are useful to verify certain elements in a series of data and to verify the data identity respectively. Identity operators can be used with the type() function to check if a variable is of a certain type or class prior to any operation.

### Abhresh S

Freelance Corporate Trainer

An Online Technical Trainer by profession! And Content writer by hobby! Interested in sharing quality knowledge to make the Industry grow better towards better success and better tomorrow! With a Guru Mantra of - "Keep Learning & Keep Practicing".

## Scala In Demand Technologies Built On Scala

The term Scala originated from “Scalable language” and it means that Scala grows with you. In recent times, Scala has attracted developers because it has enabled them to deliver things faster with fewer codes. Developers are now much more interested in having Scala training to excel in the big data field. The Scala community has grown over the years and it has now become a standard for enterprise, start-ups and universities alike. Scala is now being used by many companies and individuals to build their own new ideas. Play Framework, Akka, Apache Spark, etc are some of the tools and projects created using Scala. Scala is now the next wave of computation engines and more importance has been given to the speed processing rather than the size of the batch, and the ability to process event streaming in real-time. 1.Apache Spark Apache Spark can be considered as the replacement of MapReduce. In late 2013, Cloudera, the largest Hadoop vendor supported the idea of replacing MapReduce with Apache Spark. Spark is developed by AMPLab and it is a fast and general purpose engine for large-scale data processing. Spark effectively provides an alternative for Hadoop’s two stage MapReduce model. It has improved the performance of certain applications to 100 times with its fine grain operators, in-memory caching of intermediate data, and data flow optimization. 2. Scalding Scalding has been introduced and maintained by Twitter. It provides full benefits of Scala syntax and functional operations. Scala is a powerful language for solving functional problems. Scalding makes comprehensive use of Scala and it is an extension to cascading that enables application development with Scala. If we focus on the benefits of Scalding, data applications can be built with Scala. With simple and concise syntax code becomes easier to interpret. Scalding has filled the benefits of cascading application framework. 3. Apache Kafka Built and maintained by LinkedIn, Apache Kafka is a distributed streaming platform. Apache Kafka allows the user to publish and subscribe streams of data, just like a messaging system. Kafka is responsible for handling hundred of megabytes of read-write traffic per second from thousand of clients. It is also empowered by Scala and we can see the influence of the language. Real-time data pipelines and streaming apps can be built by using Apache Kafka. Yahoo Kafka Manager is also written in Scala and the web console is built using Play Framework. The Kafka Manager is being used by many teams including the Media Analytics team. It interacts with an actor-based, in-memory model built with Akka and Apache Curator. 4. Finagle Built by the people at twitter, Finagle can be considered as one of the best case using Scala. It is used to build high-concurrency servers and is an extensible RPC system for JVM. Finagle was intended to provide high performance, concurrency along with Scala and Java idiomatic APIs. Finagle is known for the optimal use of available system resources and high scalability through concurrency. It uses safe, simple and clean concurrent programming model which is based on Futures. All these results in safe and modular programs.
531
Scala In Demand Technologies Built On Scala

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## Web Development Using PHP And MySQL

PHP (or PHP Hypertext Preprocessor) is a server-side scripting language that is used to create dynamic web pages that can interact with databases. It is a widely-used open source language that is specifically used for web application development and can be embedded within HTML. Why PHP? The distinguishing feature of PHP is that the scripting code is executed on the server, which generates HTML that is sent back to the client. The client receives the result of executing the script without knowing the underlying code. Developers can configure the web server to process all the HTML files (containing the PHP script). PHP course is easy to learn for any newcomer, but also offers advanced programming features. Using PHP with a database system PHP, as a scripting language, is popular among web developers because of its ability to interact with database systems including Oracle and MySQL. This article discusses the use of PHP scripting language with the MySQL database. Any website can require a variety of data or information to display and to retrieve them from the database. This can include display of a simple list to the running of the website based on data stored in the database. Listed below are some examples where PHP and MySQL can be used together: • Digital Ad banners, where the PHP script can be used to retrieve a digital banner from the database, which then selects a random banner from its table records and sends it back to the calling script. The PHP script can also maintain a count of banner views and clicks from the website. • Internet forums or digital boards, which use PHP and MySQL to store and retrieve user messages. • Website designing, where the design of an entire website can be changed using a couple of PHP scripts, instead of changing and uploading each web page. The PHP script can access the MySQL database to retrieve all information about the web page. Setting up the MySQL database The procedure of setting up the MySQL database varies according to the host. Every database would require a user name and password, in order to access the database. Database administration can be done using PHP scripts or using a program like PHPMyAdmin. The next step is to create the database tables for storing the website information. Creating a database table using PHPMyAdmin is also simple. Alternatively, one can create and configure the entire database using the following PHP script: CREATE TABLE tablename { Fields } Where the Fields are coded as fieldname type(length) extra_info Example: first varchar(15) NOT NULL The following command is used in the PHP script to connect to the MySQL database: mysql_connect(localhost,$username,$password); where: • localhost is the server address on which the web site is running, • $username is the user name for the database access •$password is the password for the database access Executing PHP commands After configuring and connecting to the MySQL database, you can start executing PHP commands on the server. Following are the 2 methods of executing a PHP command: • Entering the command in PHP using the following syntax: Mysql_query($query) This form of command can be used to repeat the command simply by changing the variable. • Defining the command as a variable. The result of the operation will be assigned to the variable. Data input and output Inserting data using PHP is identical to the procedure of data input using HTML pages. The advantage of using PHP is that the script does not need to be changed for each new piece of input data. Users can also input their own data on the web page. Following is an example of an HTML page with textboxes that can be used to enter data in a form: Alternatively, you can use variables to input information into the database. Example:$first=$_POST[‘first’];$last=$_POST[‘last’];$phone=$_POST[‘phone’];$mobile=$_POST[‘mobile’];$fax=$_POST[‘fax’];$email=$_POST[’email’];$web=$_POST[‘web’]; …$query = “INSERT INTO contacts VALUES (”,’$first’,’$last’,’$phone’,’$mobile’,’$fax’,’$email’,’$web’)”; mysql_query($query); This script is saved in the insert.php file, which can be called from the HTML form. Using this method, data entered in the web page form is stored in the defined variables, which are then passed to the PHP. To display (or output) the entered data using PHP, you can use the following MySQL command with the result assigned to the variable. $query=”SELECT * FROM contacts”;$result=mysql_query(\$query); PHP provides 2 submission methods, GET and POST to get the data submitted by the form into your PHP script. GET method displays the variables and the data in the page address, while they are invisible in the POST method. For example, a script can be created that will display different web pages depending on the clicked link. yourpage.php?user=david (to show David’s page) yourpage.php?user=tom (to show Tom’s page)
3964
Web Development Using PHP And MySQL

PHP (or PHP Hypertext Preprocessor) is a server-si... Read More