1654483704
This Edureka video on 'Operators In Python' will help you establish a strong hold on all the operators in python programming language. Below are the topics covered in this video:
0:46 What Is An Operator?
5:59 Types Of Operators
6:21 Arithmetic Operators
8:02 Assignment Operators
10:36 Comparison Operators
12:20 Logical Operators
16:27 Identity Operators
18:08 Membership Operators
20:15 Bitwise Operators
Python Operators in general are used to perform operations on values and variables. These are standard symbols used for the purpose of logical and arithmetic operations. In this article, we will look into different types of Python operators.
Arithmetic operators are used to performing mathematical operations like addition, subtraction, multiplication, and division.
Operator | Description | Syntax |
---|---|---|
+ | Addition: adds two operands | x + y |
– | Subtraction: subtracts two operands | x – y |
* | Multiplication: multiplies two operands | x * y |
/ | Division (float): divides the first operand by the second | x / y |
// | Division (floor): divides the first operand by the second | x // y |
% | Modulus: returns the remainder when the first operand is divided by the second | x % y |
** | Power: Returns first raised to power second | x ** y |
# Examples of Arithmetic Operator
a = 9
b = 4
# Addition of numbers
add = a + b
# Subtraction of numbers
sub = a - b
# Multiplication of number
mul = a * b
# Division(float) of number
div1 = a / b
# Division(floor) of number
div2 = a // b
# Modulo of both number
mod = a % b
# Power
p = a ** b
# print results
print(add)
print(sub)
print(mul)
print(div1)
print(div2)
print(mod)
print(p)
Output
13
5
36
2.25
2
1
6561
Comparison of Relational operators compares the values. It either returns True or False according to the condition.
Operator | Description | Syntax |
---|---|---|
> | Greater than: True if the left operand is greater than the right | x > y |
< | Less than: True if the left operand is less than the right | x < y |
== | Equal to: True if both operands are equal | x == y |
!= | Not equal to – True if operands are not equal | x != y |
>= | Greater than or equal to True if the left operand is greater than or equal to the right | x >= y |
<= | Less than or equal to True if the left operand is less than or equal to the right | x <= y |
# Examples of Relational Operators
a = 13
b = 33
# a > b is False
print(a > b)
# a < b is True
print(a < b)
# a == b is False
print(a == b)
# a != b is True
print(a != b)
# a >= b is False
print(a >= b)
# a <= b is True
print(a <= b)
Output
False
True
False
True
False
True
Logical operators perform Logical AND, Logical OR, and Logical NOT operations. It is used to combine conditional statements.
Operator | Description | Syntax |
---|---|---|
and | Logical AND: True if both the operands are true | x and y |
or | Logical OR: True if either of the operands is true | x or y |
not | Logical NOT: True if the operand is false | not x |
# Examples of Logical Operator
a = True
b = False
# Print a and b is False
print(a and b)
# Print a or b is True
print(a or b)
# Print not a is False
print(not a)
Output
False
True
False
Bitwise operators act on bits and perform the bit-by-bit operations. These are used to operate on binary numbers.
Operator | Description | Syntax |
---|---|---|
& | Bitwise AND | x & y |
| | Bitwise OR | x | y |
~ | Bitwise NOT | ~x |
^ | Bitwise XOR | x ^ y |
>> | Bitwise right shift | x>> |
<< | Bitwise left shift | x<< |
# Examples of Bitwise operators
a = 10
b = 4
# Print bitwise AND operation
print(a & b)
# Print bitwise OR operation
print(a | b)
# Print bitwise NOT operation
print(~a)
# print bitwise XOR operation
print(a ^ b)
# print bitwise right shift operation
print(a >> 2)
# print bitwise left shift operation
print(a << 2)
Output
0
14
-11
14
2
40
Assignment operators are used to assigning values to the variables.
Operator | Description | Syntax |
---|---|---|
= | Assign value of right side of expression to left side operand | x = y + z |
+= | Add AND: Add right-side operand with left side operand and then assign to left operand | a+=b a=a+b |
-= | Subtract AND: Subtract right operand from left operand and then assign to left operand | a-=b a=a-b |
*= | Multiply AND: Multiply right operand with left operand and then assign to left operand | a*=b a=a*b |
/= | Divide AND: Divide left operand with right operand and then assign to left operand | a/=b a=a/b |
%= | Modulus AND: Takes modulus using left and right operands and assign the result to left operand | a%=b a=a%b |
//= | Divide(floor) AND: Divide left operand with right operand and then assign the value(floor) to left operand | a//=b a=a//b |
**= | Exponent AND: Calculate exponent(raise power) value using operands and assign value to left operand | a**=b a=a**b |
&= | Performs Bitwise AND on operands and assign value to left operand | a&=b a=a&b |
|= | Performs Bitwise OR on operands and assign value to left operand | a|=b a=a|b |
^= | Performs Bitwise xOR on operands and assign value to left operand | a^=b a=a^b |
>>= | Performs Bitwise right shift on operands and assign value to left operand | a>>=b a=a>>b |
<<= | Performs Bitwise left shift on operands and assign value to left operand | a <<= b a= a << b |
# Examples of Assignment Operators
a = 10
# Assign value
b = a
print(b)
# Add and assign value
b += a
print(b)
# Subtract and assign value
b -= a
print(b)
# multiply and assign
b *= a
print(b)
# bitwise lishift operator
b <<= a
print(b)
Output
10
20
10
100
102400
is and is not are the identity operators both are used to check if two values are located on the same part of the memory. Two variables that are equal do not imply that they are identical.
is True if the operands are identical
is not True if the operands are not identical
a = 10
b = 20
c = a
print(a is not b)
print(a is c)
Output
True
True
in and not in are the membership operators; used to test whether a value or variable is in a sequence.
in True if value is found in the sequence
not in True if value is not found in the sequence
# Python program to illustrate
# not 'in' operator
x = 24
y = 20
list = [10, 20, 30, 40, 50]
if (x not in list):
print("x is NOT present in given list")
else:
print("x is present in given list")
if (y in list):
print("y is present in given list")
else:
print("y is NOT present in given list")
Output
x is NOT present in given list
y is present in given list
Precedence and Associativity of Operators: Operator precedence and associativity determine the priorities of the operator.
This is used in an expression with more than one operator with different precedence to determine which operation to perform first.
# Examples of Operator Precedence
# Precedence of '+' & '*'
expr = 10 + 20 * 30
print(expr)
# Precedence of 'or' & 'and'
name = "Alex"
age = 0
if name == "Alex" or name == "John" and age >= 2:
print("Hello! Welcome.")
else:
print("Good Bye!!")
Output
610
Hello! Welcome.
If an expression contains two or more operators with the same precedence then Operator Associativity is used to determine. It can either be Left to Right or from Right to Left.
# Examples of Operator Associativity
# Left-right associativity
# 100 / 10 * 10 is calculated as
# (100 / 10) * 10 and not
# as 100 / (10 * 10)
print(100 / 10 * 10)
# Left-right associativity
# 5 - 2 + 3 is calculated as
# (5 - 2) + 3 and not
# as 5 - (2 + 3)
print(5 - 2 + 3)
# left-right associativity
print(5 - (2 + 3))
# right-left associativity
# 2 ** 3 ** 2 is calculated as
# 2 ** (3 ** 2) and not
# as (2 ** 3) ** 2
print(2 ** 3 ** 2)
Output
100.0
6
0
512
Operators are used to perform operations on variables and values.
In the example below, we use the +
operator to add together two values:
print(10 + 5)
Python divides the operators in the following groups:
Arithmetic operators are used with numeric values to perform common mathematical operations:
Operator | Name | Example | Try it |
---|---|---|---|
+ | Addition | x + y | |
- | Subtraction | x - y | |
* | Multiplication | x * y | |
/ | Division | x / y | |
% | Modulus | x % y | |
** | Exponentiation | x ** y | |
// | Floor division | x // y |
Assignment operators are used to assign values to variables:
Operator | Example | Same As | Try it |
---|---|---|---|
= | x = 5 | x = 5 | |
+= | x += 3 | x = x + 3 | |
-= | x -= 3 | x = x - 3 | |
*= | x *= 3 | x = x * 3 | |
/= | x /= 3 | x = x / 3 | |
%= | x %= 3 | x = x % 3 | |
//= | x //= 3 | x = x // 3 | |
**= | x **= 3 | x = x ** 3 | |
&= | x &= 3 | x = x & 3 | |
|= | x |= 3 | x = x | 3 | |
^= | x ^= 3 | x = x ^ 3 | |
>>= | x >>= 3 | x = x >> 3 | |
<<= | x <<= 3 | x = x << 3 |
Comparison operators are used to compare two values:
Operator | Name | Example | Try it |
---|---|---|---|
== | Equal | x == y | |
!= | Not equal | x != y | |
> | Greater than | x > y | |
< | Less than | x < y | |
>= | Greater than or equal to | x >= y | |
<= | Less than or equal to | x <= y |
Logical operators are used to combine conditional statements:
Operator | Description | Example | Try it |
---|---|---|---|
and | Returns True if both statements are true | x < 5 and x < 10 | |
or | Returns True if one of the statements is true | x < 5 or x < 4 | |
not | Reverse the result, returns False if the result is true | not(x < 5 and x < 10) |
Identity operators are used to compare the objects, not if they are equal, but if they are actually the same object, with the same memory location:
Operator | Description | Example | Try it |
---|---|---|---|
is | Returns True if both variables are the same object | x is y | |
is not | Returns True if both variables are not the same object | x is not y |
Membership operators are used to test if a sequence is presented in an object:
Operator | Description | Example | Try it |
---|---|---|---|
in | Returns True if a sequence with the specified value is present in the object | x in y | |
not in | Returns True if a sequence with the specified value is not present in the object | x not in y |
Bitwise operators are used to compare (binary) numbers:
Operator | Name | Description |
---|---|---|
& | AND | Sets each bit to 1 if both bits are 1 |
| | OR | Sets each bit to 1 if one of two bits is 1 |
^ | XOR | Sets each bit to 1 if only one of two bits is 1 |
~ | NOT | Inverts all the bits |
<< | Zero fill left shift | Shift left by pushing zeros in from the right and let the leftmost bits fall off |
>> | Signed right shift | Shift right by pushing copies of the leftmost bit in from the left, and let the rightmost bits fall off |
#python #programming
1677668905
Mocking library for TypeScript inspired by http://mockito.org/
mock
) (also abstract classes) #examplespy
) #examplewhen
) via:verify
)reset
, resetCalls
) #example, #examplecapture
) #example'Expected "convertNumberToString(strictEqual(3))" to be called 2 time(s). But has been called 1 time(s).'
)npm install ts-mockito --save-dev
// Creating mock
let mockedFoo:Foo = mock(Foo);
// Getting instance from mock
let foo:Foo = instance(mockedFoo);
// Using instance in source code
foo.getBar(3);
foo.getBar(5);
// Explicit, readable verification
verify(mockedFoo.getBar(3)).called();
verify(mockedFoo.getBar(anything())).called();
// Creating mock
let mockedFoo:Foo = mock(Foo);
// stub method before execution
when(mockedFoo.getBar(3)).thenReturn('three');
// Getting instance
let foo:Foo = instance(mockedFoo);
// prints three
console.log(foo.getBar(3));
// prints null, because "getBar(999)" was not stubbed
console.log(foo.getBar(999));
// Creating mock
let mockedFoo:Foo = mock(Foo);
// stub getter before execution
when(mockedFoo.sampleGetter).thenReturn('three');
// Getting instance
let foo:Foo = instance(mockedFoo);
// prints three
console.log(foo.sampleGetter);
Syntax is the same as with getter values.
Please note, that stubbing properties that don't have getters only works if Proxy object is available (ES6).
// Creating mock
let mockedFoo:Foo = mock(Foo);
// Getting instance
let foo:Foo = instance(mockedFoo);
// Some calls
foo.getBar(1);
foo.getBar(2);
foo.getBar(2);
foo.getBar(3);
// Call count verification
verify(mockedFoo.getBar(1)).once(); // was called with arg === 1 only once
verify(mockedFoo.getBar(2)).twice(); // was called with arg === 2 exactly two times
verify(mockedFoo.getBar(between(2, 3))).thrice(); // was called with arg between 2-3 exactly three times
verify(mockedFoo.getBar(anyNumber()).times(4); // was called with any number arg exactly four times
verify(mockedFoo.getBar(2)).atLeast(2); // was called with arg === 2 min two times
verify(mockedFoo.getBar(anything())).atMost(4); // was called with any argument max four times
verify(mockedFoo.getBar(4)).never(); // was never called with arg === 4
// Creating mock
let mockedFoo:Foo = mock(Foo);
let mockedBar:Bar = mock(Bar);
// Getting instance
let foo:Foo = instance(mockedFoo);
let bar:Bar = instance(mockedBar);
// Some calls
foo.getBar(1);
bar.getFoo(2);
// Call order verification
verify(mockedFoo.getBar(1)).calledBefore(mockedBar.getFoo(2)); // foo.getBar(1) has been called before bar.getFoo(2)
verify(mockedBar.getFoo(2)).calledAfter(mockedFoo.getBar(1)); // bar.getFoo(2) has been called before foo.getBar(1)
verify(mockedFoo.getBar(1)).calledBefore(mockedBar.getFoo(999999)); // throws error (mockedBar.getFoo(999999) has never been called)
let mockedFoo:Foo = mock(Foo);
when(mockedFoo.getBar(10)).thenThrow(new Error('fatal error'));
let foo:Foo = instance(mockedFoo);
try {
foo.getBar(10);
} catch (error:Error) {
console.log(error.message); // 'fatal error'
}
You can also stub method with your own implementation
let mockedFoo:Foo = mock(Foo);
let foo:Foo = instance(mockedFoo);
when(mockedFoo.sumTwoNumbers(anyNumber(), anyNumber())).thenCall((arg1:number, arg2:number) => {
return arg1 * arg2;
});
// prints '50' because we've changed sum method implementation to multiply!
console.log(foo.sumTwoNumbers(5, 10));
You can also stub method to resolve / reject promise
let mockedFoo:Foo = mock(Foo);
when(mockedFoo.fetchData("a")).thenResolve({id: "a", value: "Hello world"});
when(mockedFoo.fetchData("b")).thenReject(new Error("b does not exist"));
You can reset just mock call counter
// Creating mock
let mockedFoo:Foo = mock(Foo);
// Getting instance
let foo:Foo = instance(mockedFoo);
// Some calls
foo.getBar(1);
foo.getBar(1);
verify(mockedFoo.getBar(1)).twice(); // getBar with arg "1" has been called twice
// Reset mock
resetCalls(mockedFoo);
// Call count verification
verify(mockedFoo.getBar(1)).never(); // has never been called after reset
You can also reset calls of multiple mocks at once resetCalls(firstMock, secondMock, thirdMock)
Or reset mock call counter with all stubs
// Creating mock
let mockedFoo:Foo = mock(Foo);
when(mockedFoo.getBar(1)).thenReturn("one").
// Getting instance
let foo:Foo = instance(mockedFoo);
// Some calls
console.log(foo.getBar(1)); // "one" - as defined in stub
console.log(foo.getBar(1)); // "one" - as defined in stub
verify(mockedFoo.getBar(1)).twice(); // getBar with arg "1" has been called twice
// Reset mock
reset(mockedFoo);
// Call count verification
verify(mockedFoo.getBar(1)).never(); // has never been called after reset
console.log(foo.getBar(1)); // null - previously added stub has been removed
You can also reset multiple mocks at once reset(firstMock, secondMock, thirdMock)
let mockedFoo:Foo = mock(Foo);
let foo:Foo = instance(mockedFoo);
// Call method
foo.sumTwoNumbers(1, 2);
// Check first arg captor values
const [firstArg, secondArg] = capture(mockedFoo.sumTwoNumbers).last();
console.log(firstArg); // prints 1
console.log(secondArg); // prints 2
You can also get other calls using first()
, second()
, byCallIndex(3)
and more...
You can set multiple returning values for same matching values
const mockedFoo:Foo = mock(Foo);
when(mockedFoo.getBar(anyNumber())).thenReturn('one').thenReturn('two').thenReturn('three');
const foo:Foo = instance(mockedFoo);
console.log(foo.getBar(1)); // one
console.log(foo.getBar(1)); // two
console.log(foo.getBar(1)); // three
console.log(foo.getBar(1)); // three - last defined behavior will be repeated infinitely
Another example with specific values
let mockedFoo:Foo = mock(Foo);
when(mockedFoo.getBar(1)).thenReturn('one').thenReturn('another one');
when(mockedFoo.getBar(2)).thenReturn('two');
let foo:Foo = instance(mockedFoo);
console.log(foo.getBar(1)); // one
console.log(foo.getBar(2)); // two
console.log(foo.getBar(1)); // another one
console.log(foo.getBar(1)); // another one - this is last defined behavior for arg '1' so it will be repeated
console.log(foo.getBar(2)); // two
console.log(foo.getBar(2)); // two - this is last defined behavior for arg '2' so it will be repeated
Short notation:
const mockedFoo:Foo = mock(Foo);
// You can specify return values as multiple thenReturn args
when(mockedFoo.getBar(anyNumber())).thenReturn('one', 'two', 'three');
const foo:Foo = instance(mockedFoo);
console.log(foo.getBar(1)); // one
console.log(foo.getBar(1)); // two
console.log(foo.getBar(1)); // three
console.log(foo.getBar(1)); // three - last defined behavior will be repeated infinity
Possible errors:
const mockedFoo:Foo = mock(Foo);
// When multiple matchers, matches same result:
when(mockedFoo.getBar(anyNumber())).thenReturn('one');
when(mockedFoo.getBar(3)).thenReturn('one');
const foo:Foo = instance(mockedFoo);
foo.getBar(3); // MultipleMatchersMatchSameStubError will be thrown, two matchers match same method call
You can mock interfaces too, just instead of passing type to mock
function, set mock
function generic type Mocking interfaces requires Proxy
implementation
let mockedFoo:Foo = mock<FooInterface>(); // instead of mock(FooInterface)
const foo: SampleGeneric<FooInterface> = instance(mockedFoo);
You can mock abstract classes
const mockedFoo: SampleAbstractClass = mock(SampleAbstractClass);
const foo: SampleAbstractClass = instance(mockedFoo);
You can also mock generic classes, but note that generic type is just needed by mock type definition
const mockedFoo: SampleGeneric<SampleInterface> = mock(SampleGeneric);
const foo: SampleGeneric<SampleInterface> = instance(mockedFoo);
You can partially mock an existing instance:
const foo: Foo = new Foo();
const spiedFoo = spy(foo);
when(spiedFoo.getBar(3)).thenReturn('one');
console.log(foo.getBar(3)); // 'one'
console.log(foo.getBaz()); // call to a real method
You can spy on plain objects too:
const foo = { bar: () => 42 };
const spiedFoo = spy(foo);
foo.bar();
console.log(capture(spiedFoo.bar).last()); // [42]
Author: NagRock
Source Code: https://github.com/NagRock/ts-mockito
License: MIT license
1619565060
What is a ternary operator: The ternary operator is a conditional expression that means this is a comparison operator and results come on a true or false condition and it is the shortest way to writing an if-else statement. It is a condition in a single line replacing the multiline if-else code.
syntax : condition ? value_if_true : value_if_false
condition: A boolean expression evaluates true or false
value_if_true: a value to be assigned if the expression is evaluated to true.
value_if_false: A value to be assigned if the expression is evaluated to false.
How to use ternary operator in python here are some examples of Python ternary operator if-else.
Brief description of examples we have to take two variables a and b. The value of a is 10 and b is 20. find the minimum number using a ternary operator with one line of code. ( **min = a if a < b else b ) **. if a less than b then print a otherwise print b and second examples are the same as first and the third example is check number is even or odd.
#python #python ternary operator #ternary operator #ternary operator in if-else #ternary operator in python #ternary operator with dict #ternary operator with lambda
1626775355
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.
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.
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
1602968400
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.
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
1602666000
Today you’re going to learn how to use Python programming in a way that can ultimately save a lot of space on your drive by removing all the duplicates.
In many situations you may find yourself having duplicates files on your disk and but when it comes to tracking and checking them manually it can tedious.
Heres a solution
Instead of tracking throughout your disk to see if there is a duplicate, you can automate the process using coding, by writing a program to recursively track through the disk and remove all the found duplicates and that’s what this article is about.
But How do we do it?
If we were to read the whole file and then compare it to the rest of the files recursively through the given directory it will take a very long time, then how do we do it?
The answer is hashing, with hashing can generate a given string of letters and numbers which act as the identity of a given file and if we find any other file with the same identity we gonna delete it.
There’s a variety of hashing algorithms out there such as
#python-programming #python-tutorials #learn-python #python-project #python3 #python #python-skills #python-tips