university notes Lecture - 1 (Python) E-Notes.pptx
- 1. Lecture - 1 Training On Python
- 2. Introduction To Python • Python is powerful and general purpose programming language, developed by the Guido Van Rossum (1989). • Guido Van Rossum developed python language at mathematical research institute called ‘CWI’. • CWI is located at Netherland. • Guido developed python language by taking the different language features like:- Procedure oriented programming language--C Object oriented programming language--C++, Java Scripting language-- Shell script, perl. Modular programming language--Modula – 3 Note:- Guido Van Rossum made available python language to the public in 1991.
- 3. Applications Developed By Using Python Web Development. Machine Learning & Artificial Intelligence. Data Science & Data Visualization Desktop GUI Game Development Web Scrapping Applications Business Applications Embedded Applications IOT (Internet Of Things)
- 4. Difference Between Programming And Scripting Languages Scripting Language Programming Language Scripting language are interpreter based languages. Programming language are compiler based languages. Scripting language programs (or) applications explicit compilation is not required. It requires explicit compilation. Scripting language programs (or) applications directly we can run. Programming language programs (or) applications we can’t run without compilation. Scripting language programs (or) applications take larger time to execute. Programming language programs (or) applications take less time to execute. Ex. Shell script, perl… Ex. C, C++, Java,…..
- 6. 1. Simple And Easy To Learn The syntaxes of the python language are very simple. Anybody can remember the python language syntaxes, rules and regulations very easily. By developing the python programs (or) applications programmers need not to focus on the syntaxes. Instead of focusing on syntaxes they can focus on the business logic implementation. The elegant syntaxes of the python language make the people to learn python in easiest manner. Without having any other programming language knowledge directly anybody can learn python language. The simple and powerful syntax of the python language makes the programmers to express their business logic is less lines of code. Because of simple feature of python language project development cost, development time and maintenance cost will become less.
- 7. 2. Platform Independent The Python applications which are developed on one platform are going to execute on irrespective of platforms without making any changes in the python applications. To achieve the portability feature with respect to every o.s. seperate python software is developed for every version of python.
- 8. 3. Free, Open Source And Re-distribution Anybody can use the python software without purchasing license agreement of python. Anybody can read the python source code and they can do the modifications in the python source code and we can redistribute that code to others.
- 9. 4. Supporting Procedural And Object Oriented Programming Python language supports both p.o.p and o.o.p language features. If we develop any application according to the oops principles then that application will get security, flexibility & reusability. Different oops principles are: i.) Encapsulation ii.) Polymorphism iii.) Inheritance iv.) Abstraction Python supports oops principles because of that reason python applications will get the security, flexibility and reusability.
- 10. 5. Interpreted Language Python applications don’t require explicit compilation so that compiler is not required for in python software. Directly we can run the python applications without compiling explicit. Python interpreter is responsible for execution of python applications. Whenever we run python applications python interpreter will check the syntax error. If no syntax error python interpreter converts that code in the form of intermediate code in the form of low level format and executes it. The intermediate code of python applications is known as byte code. The extension for the byte code file is .pyc.
- 11. 6. Extensible Python application execution is slower compared to c, c++ programs execution. To overcome the above problem we can implement some logics by using c, c++ language and we can use c, c++ programs into python application. Python source code doesn’t contain security i.e., anybody can read python code and they can do the modifications in the source code. If we want to provide security to the some part (logic) or some algorithm of python application then we represent that code on logic (or) algorithm by using c (or) c++ languages and we use that code into python application.
- 12. 7. Embeddable We can use the python code into the other language programs such as c, c++, java .. In order to provide the scripting capabilities to other language programs / applications we use python code into those applications.
- 13. 8.Rich In Built-in Libraries Python language is providing huge built – in libraries. Python developers can use built-in libraries in their applications. By using built-in libraries application development will become faster. Third party people developed libraries, modules we can add to python software and used into python applications.
- 14. Installation Of Python Interpreter Download the required python 3.7.0 software from following website: http://www.python.org/downloads Click on the downloaded installer file and install it.
- 15. Development Of Python Applications (or) Programs We can develop python applications / programs in two modes. They are Interactive mode Batch mode
- 16. Interactive Mode Interactive mode is a command line shell. In command line shell if we write any python statement immediately that statement will execute and gives the result. Interactive mode is used to test the features of the python (what python can do?) Note:- Interactive mode is not used for development of business applications.
- 17. Batch Mode In batch mode we write group of python statements in any one of the editors (or) IDE’s. After writing the group of python statements in anyone of the editor / IDE we save the file with extension “.py” or “.pyw”. After developing the .py (or) .pyw files we submit those files to the python interpreter directly. Batch mode is used for development of business application. Write the following code:- i=1000 j=200 print(i+j) print (i-j) Save the above file with demo.py in c-drive. Open the cmd prompt C:>python demo.py
- 18. Input & Output In Python In python we use print() method to display output. E.g. print(“Hello, World”) print(“Summation=”,(10+2)) In python we use input() method to take input from user. By default input() method take string type input. But if you need another type of input you must typecast it. E.g. name=input(“Enter your name : ”) #String input a=int(input(“Enter first no : ”)) #int input
- 19. Example Application #WAP in python to make a simple calculator a=int(input(“Enter first no : ”)) b=int(input(“Enter second no : ”)) print(“Summation=”,(a+b)) print(“Subtraction=”,(a-b)) print(“Multiplication=”,(a*b)) print(“Division=”,(a/b)) O/P:- Enter first no : 10 Enter second no : 5 Summation=15 Subtraction=5 Multiplication=50 Division=2