DEV Community: mahdin1209

INTRODUCTION TO PYTHON (For and while loops and STRINGS)

mahdin1209 — Fri, 02 Dec 2022 12:54:30 +0000

While loops:

With the while loop we can execute a set of statements as long as a condition is true.

break statement:
It is a loop control statement. Suppose you want to terminate a loop and skip to the next code after the loop; break will help you do that. It is used after the loop statements.

continue statement
With the continue statement we can stop the current iteration, and continue with the next.

for loops:

A for loop is used for iterating over a sequence (that is either a list, a tuple, a dictionary, a set, or a string).

Range() function
The range() function returns a sequence of numbers, starting from 0 by default, and increments by 1 (by default), and stops before a specified number.
range(start,stop,step)
start: Optional. An integer number specifying at which position to start. Default is 0
stop: Required. An integer number specifying at which position to stop (not included).
step: Optional. An integer number specifying the incrementation. Default is 1.

STRINGS

A string (str) in Python is a single character or a collection of characters. Strings in python usually represented by double or single quotation.

If we want to print multiple lines of strings, we just have to follow these steps:

len() function
The len() function returns the length of a string:

Indexing
We can access every element in strings by indexing. There are two types of indexing one is positive indexing and another one is negative indexing.
Positive indexing:
Positive indexing starts from 0 and ends at (length of a string -1).

Negative indexing:
Negative indexing starts from -1 and -length of string.

_Strings are immutable. Once a string is created the characters on it can't be changed or deleted. _

INTRODUCTION PART 2

mahdin1209 — Fri, 02 Dec 2022 11:12:09 +0000

Today we are going to learn about some basics of python like indentation and branching.

Indentation

So, first of all indentation refers to the spaces at the beginning of a code line. It mainly indicates a block of code. A code block (body of a condition, loop, function etc) starts with indentation and ends with the first unintended line. In python indentation is very important as it will give you an error if you skip the indentation.

Branching

Python programming language provides following types of decision making or branching statements in Python. Python programming language provided decision making statements or branching statements as follows.

if statements
if...else statements
if....elif....else statements
nested if statements

if statements
It is used to decide whether a certain statement or block of statements will be executed or not. If a certain condition is true, then a block of statement is executed otherwise not.

if...else statements
The else statement is always used with if statement. It is used to execute block of codes whenever if condition gives false result.

if...elif...else statements
For adding more conditions, elif statement in used. The program first checks if condition. When found false, it checks elif conditions. If all elif conditions are found false, then else code block is executed.

nested if statements
A nested if statement is an if statement placed inside another if statement. In a nested if construct, you can have an if...elif...else construct inside another if...elif...else construct.

print() function example

There are some functions which are probably used in print().

sep="seperator"
end="end"

INTRODUCTION

mahdin1209 — Fri, 02 Dec 2022 05:44:29 +0000

https://dev.to/amahdin2/python-for-beginners-part-1-2n0j