1. Python language

 

*Introduction to python: 

 Python is a programming language used to create software & it is easy to learn. 

Guido Van Rossum was the founder of the python language. He liked a tv serial python. Thus he named this language python. 

* print ( ) function: 

 It is used to print something on the screen. 

E.g.  print("Hello World")  

             or 

   print('Hello World') 

Output: Hello World 

* String : 

Collection of characters inside the "double quotes " or 'single quotes' 

Note: You can use 'single quotes' inside "double quotes"     or  "Double quotes" inside 'single quotes' . 

* Escape sequence: 

Escape sequences allow you to add special characters in strings. To do this, simply add  backslash ( \ ) before the character you want to escape. Table for escape sequences are : 

Eg.  print("My name is \n Pankaj Kumar" ) 

Output: 

My name is

Pankaj Kumar

Backspace(\b ) command is used to delete a word. 

E.g. print("hell\blo")

Output:   hello  ( But in input there was three lll , it is the magic of the backspace escape sequence.) 

* Comment: 

A comment is a text that doesn't affect the outcome of a code, it is just a piece of text to let someone to know that what you have done in a program. 

# symbol is used for comment anything. 

E.g. 

# This is a comment

print("Pankaj Kumar") 

Output: 

Pankaj Kumar

* Exercise question: 

print output as :        \" \n \t \' 

Solution: 

print(" \\\" \\n \\t \\\' ") 

* Raw string: 

The raw string is created by prefixing a string with r or R . Python raw string treats backslash ( \ )as a textual character. This is useful when we want to have a string that contains backslash & don't want to be treated as an escape character. 

Eg.  Input: 

print(r"\" \n \t \' ")

Output:  \" \n \t \'

* How to print Emoji: 

All Emoji have different commands. Command of some emoji are: 

Eg: print(" \ U0001F602")

* How to use python as a calculator: 

* In the last operation i.e. **  means the power of something. Eg.  2** 3 = 2^3 = 8

* If we want the root of any digit. Eg. I want the root of print(2** 0.5) = 1.41421356237

But I want to take a round off the value of under root 2. Then we have to use round off function: 

print (round(2**0.5,4)) 

Output: 1.4142 

* BODMAS rule plays an important role in the calculation.

Here B= Barakat,  O = order, D = Division, M = Multiplication, A = Addition, S = Subtraction. 

* \\ will print as \ in output. & \\\\ will be print as \\ double backslash in output.