Every day we make decisions. When I get up in the morning, I need my shake. Now, for the shake, I need 500 ml Milk, 100 gms of Oats, 1 Banana, 1 Kiwi, and 1 Apple. In case, I don’t have any one of these, it can spell trouble. What’s the trouble ? I cannot make my shake.
In programming, we have a similar structure to situations such as these. Decision making is done with a set of statements called if, else-if, and else.
If: If a certain condition is met, we perform a block of code. Else-if: If the IF condition is not met, we perform the code written in else-if Else: If the IF condition, and the ELSE-IF condition are both not met, we perform this block of code.
Statement & Description
An if statement consists of a boolean expression followed by one or more statements.
An elif statement is python’s way of saying “if the previous conditions were not true, then try this condition”.
The else keyword catches anything which isn’t caught by the preceding conditions.
A more picturesque, and descriptive version can be seen in this image below:
x = 33 y = 200 if y > x: print(“y is greater than x”)
y is greater than x
Please note the indentation. In Python, we use indentations as a way of saying that the code which follows the statement is enclosed. In other programming languages, we tend to use braces, or a parenthesis for the same. In python, things are slightly simpler, and we use indentations.
x = 56 y = 56 if x > y: print(“x is greater than y”) elif x == y: print(“x and y are equal”)
x and y are equal
From the above example, we can see that because a and b both have equal values, the first block was not satisfied. Instead, the second block of code under elif, has been executed.
x = 100 y = 50 if x > y: print(“x is greater than y”) elif x == y: print(“x and y are equal”) else: print(“x is greater than y”)
The heart, the soul, and the foundation of any programming language, are it’s operators. They help build the logic, and transform your ideas into functioning models. They can manipulate values, functions, and help achieve our targets when used effectively.
Types of Operators
Python language supports the following types of operators.
Now, we shall look at each arithmetic operator with examples, so that it will be a lot easier for one to understand, how does Python, and their operators, really work!
Python Arithmetic Operators
Let’s assume we have two variable, a =5 and b = 10. Thus:
Adds values on either side of the operator.
a + b = 15
Subtracts right hand operand from left hand operand.
a – b = -5
Multiplies values on either side of the operator
a * b = 50
Divides left hand operand by right hand operand
b / a = 2
Divides left hand operand by right hand operand and returns remainder
b % a = 0
Performs exponential (power) calculation on operators
a**b = 5 to the power 10
Floor Division – 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) −
The word variable in itself speaks dynamism. It’s value, quantity, and essence, can change from time to time. In programming as well, your value changes from time to time.
In Python, variables are used to store data, like string, numbers, date-time etc. When you create a variable, a little portion is reserved within your computer memory to store this value of the variable. The value of a variable has to be assigned by you.
Types of variables
Python has five standard data types:
Creating a variable
In Python, a variable does not need to be declared while creating or before adding a value to it. Python variables are usually dynamically typed, that is, the type of the variable is interpreted during run-time and you don’t need to specify the type of a variable.
The following program shows how to use string and integer type variables:
x = 10 # Integer variable y = “Hello World” # String variable # Displaying variables value print(x) print(y)
10 Hello World
Checking the type of a variable
With the method type(), we can know the type of variable we have created. It could be int, str, is used to get the type of a created variable.
var1 = ‘Hello World’ print(type(var1))
ImportantRules for Variables
Variables cannot start with a number, but can be Alpha-Numeric. Additionally, they also support underscores – hence the total range is from A-Z, a-z, 0-9, and _.
Variables are strictly case-sensitive, thus You and you are different variables
Data Type Conversion
Sometimes, due to functional reasons, we need to convert variables. For this purpose, python is quite straight forward. To convert between types, you simply use the type name as a function. A common industry jargon is ‘Type Casting‘.
There are several built-in functions to perform conversion from one data type to another. These functions return a new object, with the changed data type 🙂.
Function & Description
int(x ): Converts x to an integer.
long(x): Converts x to a long integer.
float(x): Converts x to a floating-point number.
str(x): Converts object x to a string representation.
tuple(s): Converts s to a tuple.
list(s): Converts s to a list.
set(s): Converts s to a set.
dict(d): Creates a dictionary. d must be a sequence of (key,value) tuples.
You have no idea how long I have waited to have my own portal in order to share information, with one, and all. With a lot of patience, time, and effort, I’d like to begin my journey of being an open book, solving some of your problems, and in that process also learning a lot more from you.
To begin with, I would like to introduce Python to you as a concept I like to call SEQL – Simple Elegant Quick Learn. So instead of SQL, we have SEQL.
Python is a popular programming language. It was created by Guido van Rossum, and released in 1991, and has a wide array of uses, particularly:
Owing to it’s Simple syntax, and an Elegant programming structure, it is Quick to execute and Learn. Over the course of my forthcoming posts, you shall come across a wide range of tutorials, quick solutions, tips, and tricks, that I have documented, learned, and experienced over time.
With my trivial, yet foundational, exposure to Python, I want to document my understanding of programming, and make it as easy for you to grasp the fundamental concepts of programming.
In case you have any doubts, feel free to write down your questions in the comments below. I will try and respond to each one of them.
Before I leave, one has to cut the ribbon by a simple saying….wait for it….”Hello World”.