Introduction To python (comments, variables, data types and numbers.)
Tags: python, beginners
Published: 2022-03-03 11:32:55

Python is one of the most widely used programming languages. Guido van Rossum created it, and it was released in 1991. It's used for server-side web development, software development, mathematics, and system programming just to mention.

Python is well-known for its general-purpose character, which makes it suitable for and the finest solution provider in practically any software development domain. Python is used in a variety of developing fields, including Data Science and Big Data Analytics. It is the most popular programming language and may be used to create any application.

A Python script which is essentially a file that contains a python code should have an extension .py and can be run from the command line by typing python file_name.py

**characteristic Of Python**

- Python is a free and open source programming language that can be downloaded from the official website, with even its source code available.
- Python can be used for rapid prototyping, or for production-ready software development.
- Platform Independent, write once and run anywhere
- python can connect to database systems. It can also read and modify files.

**python is used for **

- web development (server-side),
- software development,
- mathematics,
- system scripting.

**Python Syntax compared to other programming languages**

Python was designed for readability, and has some similarities to the English language with influence from mathematics.
Python uses new lines to complete a command, as opposed to other programming languages which often use semicolons or parentheses.
Python relies on indentation, using whitespace, to define scope; such as the scope of loops, functions and classes. Other programming languages often use curly-brackets for this purpose.

**My First Python Program**

```
print ("hello world")
```
then run the program and the output below will be displayed

```
hello World
```
**Python Comments**

Comments can be used to explain Python code.

Comments can be used to make the code more readable.

Comments can be used to prevent execution when testing code.

To begin creating a comment in python we utilize the hash symbol (#)
If we have comments that span multiple lines, multi-line comments we can use the hash symbol at the start of each line . Another option is to use triple quotes such as ''' or """

```
# This is a single line comment

'''
multiline comment
This comment is written in more than one line
'''
```
A comment does not have to be text that explains the code, it can also be used to prevent Python from executing code:

```
#print("Good, Mercedes!")
print("Cheers, lasucbt")
```
when you run your code the output below will be displayed

```
Cheers, lasucbt
```
**conclusion**
Comments can be used to explain Python code. Comments can be used to make the code more readable. Comments can be used to prevent execution when testing code.

**Python Variables**

Variables are names that are connected to a specific object in Python. They keep a reference to the memory address where an item is stored, often known as a pointer.
Variables are containers for storing data values.
The syntax is as follows:

```
variable_name = variable_value
```
_Creating Variables_
Python has no command for declaring a variable.

A variable is created the moment you first assign a value to it.

```
x = 5
y = "John"
print(x)
print(y)
```
when you run the code the output below will be displayed

```
5
John
```
**Variable Names**
A variable can have a short name (like x and y) or a more descriptive name (age, carname, total_volume). Rules for Python variables:
A variable name must start with a letter or the underscore character
A variable name cannot start with a number
A variable name can only contain alpha-numeric characters and underscores (A-z, 0-9, and _ )
Variable names are case-sensitive (age, Age and AGE are three different variables)

Always name your variables in a way that is both intuitive and readable.
Uppercase and lowercase letters (A-Z, a-z), numerals (0-9), and the underscore character (_) can all be used in variable names.
Variable names may contain digits, but the initial character must not be a numeric.

Variables do not require declaration. Python is a dynamically typed language since their data types are deduced from their assignment statement. This means that throughout the code, different data types might be given to the same variable.

Below are examples:

```
first_name = "elijah"
print(first_name)

middle_name = "khalifa"
print(middle_name)

last_name = "joy"
print(last_name)
```
Run the code and the output below will be displayed

```
elijah
khalifa
joy
```
Python allows you to assign values to multiple variables in one line:

```
x, y, z = "Orange", "Banana", "Cherry"
print(x)
print(y)
print(z)
```
Run the code and the output below will be displayed

```
Orange
Banana
Cherry
```
**Conclusion**
python variables has different segments under it like 

- variable names
- assign multiple variables
- output variables
- global variables

 Like any other programming language, the concept of variables plays a significant role in python. The classified number of functionalities and flexibility in coding them make variables more precise entities for access in the python programming language.
A Python variable is a reserved memory location to store values. In other words, a variable in a python program gives data to the computer for processing.

**Python Data Types**
Built-in Data Types
In programming, data type is an important concept.

Variables can store data of different types, and different types can do different things.

Python has the following data types built-in by default, in these categories:

``Text Type:	str
Numeric Types:	int, float, complex
Sequence Types:	list, tuple, range
Mapping Type:	dict
Set Types:	set, frozenset
Boolean Type:	bool
Binary Types:	bytes, bytearray, memoryview``

**Python Numbers**

There are three numeric types in Python:
``int
float
complex``.