Article Categories
- All Categories
-
Data Structure
-
Networking
-
RDBMS
-
Operating System
-
Java
-
MS Excel
-
iOS
-
HTML
-
CSS
-
Android
-
Python
-
C Programming
-
C++
-
C#
-
MongoDB
-
MySQL
-
Javascript
-
PHP
Programming Articles
Page 678 of 2544
How can a Python subclass control what data is stored in an immutable instance?
For this, at first understand what is __new__() method in Python. When subclassing an immutable type, override the __new__() method instead of the __init__() method. The __new__ method gets called when an object is created whereas the __init__ method will be called to initialize the object. These are magic methods. The magic methods that allow us to do some pretty neat tricks in object-oriented programming. They are also called Dunder methods. These methods are identified by two underscores (__) used as prefix and suffix. Display the magic methods inherited by int class Example Using the fir(), we can print the ...
Read MoreWhy does the result of id() appear to be not unique in Python?
The id() method in Python return the identity of an object i.e. a unique id for the specified object. Now, you would be wondering, what is this id(). The id here is the object's memory address, an integer guaranteed to be unique and constant for this object during its lifetime. Two objects with non-overlapping lifetimes may have the same id() value. Syntax id(object) This object can be object, String, Number, List, etc. Unique id of List Object Example In this example, we will get the unique id of the list object using the id() − myList = ["john", "tom", ...
Read MoreWhen can I rely on identity tests with the is operator in Python?
Example The is operator is an identity operator in Python. It tests for object identity. Let us see an example − x = ["Paul", "Mark"] y = ["Paul", "Mark"] z = x # Python IS operator print(x is z) Output True Let’s say we consider another example, wherein the test a is b is equivalent to − id(a) == id(b) The key property of an identity test is that an object is always identical to itself, a is a always returns True. Identity tests are usually faster than equality tests. And unlike equality tests, identity tests ...
Read MoreHow do I create static class data and static class methods in Python?
Python includes the concept of static class data and static class methods. The static class data Here, define a class attribute for the static class data. Explicitly use the class name in the assignment, if you want to assign a new value to the attribute − class Demo: count = 0 def __init__(self): Demo.count = Demo.count + 1 def getcount(self): return Demo.count We can also return the following instead return ...
Read MoreHow can I organize my Python code to make it easier to change the base class?
Before learning how to change the base class, let us first understand the concept of base and derived class in Python. We will learn about Base and Derived class using the concept of Inheritance. In multiple inheritance, the features of all the base classes are inherited into the derived class. Let us see the syntax − Syntax Class Base1: Body of the class Class Base2: Body of the class Class Base3: Body of the class . . . Class BaseN: Body of the class Class ...
Read MoreHow do I get int literal attribute instead of SyntaxError in Python?
To get int literal attribute instead of SyntaxError, use a space or parenthesis. The int literal is a part if Numeric Literals in Python. Numeric Literals also includes the following four different numerical types − int (signed integers) − They are often called just integers or ints, are positive or negative whole numbers with no decimal point. long (long integers ) − Also called longs, they are integers of unlimited size, written like integers and followed by an uppercase or lowercase L. float (floating point real values) − Also called floats, they represent real numbers and are written with ...
Read MoreWhy does -22 // 10 return -3 in Python?
In Python, -22//10 returns -3 because of the concept of Floor Division i.e. Double Slash Operator. The // is the Double Slash i.e. Arithmetic Operator. Let us first understand about it. Floor Division in Python The division of operands where the result is the quotient in which the digits after the decimal point are removed. But if one of the operands is negative, the result is floored, i.e., rounded away from zero (towards negative infinity). In Python, the // is the double slash operator i.e. Floor Divison. The // operator is used to perform division that rounds the result down ...
Read MoreHow it is possible to write obfuscated oneliners in Python?
Yes, it is possible to write obfuscated one-liners in Python using Lambda. Before moving further, let us first understand what are Lambdas in Python. Python Lambda The Lambda expressions allow defining anonymous functions. A lambda function is an anonymous function i.e. a function without a name. Let us see the syntax − lambda arguments: expressions The keyword lambda defines a lambda function. A lambda expression contains one or more arguments, but it can have only one expression. Example Let us see an example − myStr = "Thisisit!" (lambda myStr : print(myStr))(myStr) Output Thisisit! Merge Elements in a ...
Read MoreIs there an equivalent of C’s “?:” ternary operator in Python?
Yes, we can work around C Language’s ternary operator in Python as well i.e. a similar way do exist. Let us first see an example of C Language’s ternary operator − Example #include int main() { int x = 10; int y; y = (x == 1) ? 20: 30; printf( "Value of y = %d", y ); y = (x == 10) ? 20: 30; printf( "Value of y = %d", y ); } Output Value ...
Read MoreMy Python program is too slow. How do I speed it up?
If your Python program is too slow, you can follow the below given tips and tricks − Abstraction Avoid excessive abstraction, especially under the form of tiny functions or method. Abstractions tend to create indirections and force the interpreter to work more. If the levels of indirection outweigh the amount of useful work done, your program will be slower Avoid Looping Overhead If the body of your loop is simple, the interpreter overhead of the for loop itself can be a substantial amount of the overhead. This is where the map function works in a better way. The only restriction ...
Read More